Cyanide

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Cyanide

Cyanide anion

Names
Preferred IUPAC name Cyanide
Systematic IUPAC name Nitridocarbonate(II)

Hazards
Main hazards	The cyanide ion CN− is one of the most poisonous chemicals. It may cause death in minutes.

In chemistry, a cyanide (from Greek kyanos 'dark blue') is a chemical compound that contains a C≡N functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom.

In inorganic cyanides, the cyanide group is present as the cyanide anion ⁻C≡N. This anion is extremely poisonous. Soluble salts such as sodium cyanide (NaCN) and potassium cyanide (KCN) are highly toxic. Hydrocyanic acid, also known as hydrogen cyanide, or HCN, is a highly volatile liquid that is produced on a large scale industrially. It is obtained by acidification of cyanide salts.

Organic cyanides are usually called nitriles. In nitriles, the −C≡N group is linked by a single covalent bond to carbon. For example, in acetonitrile (CH₃−C≡N), the cyanide group is bonded to methyl (−CH₃). Although nitriles generally do not release cyanide ions, the cyanohydrins do and are thus toxic.

Bonding

The cyanide ion ⁻C≡N is isoelectronic with carbon monoxide ⁻C≡O⁺ and with molecular nitrogen N≡N. A triple bond exists between C and N. The negative charge is concentrated on carbon C.

Occurrence

In nature

Removal of cyanide from cassava in Nigeria.

Cyanides are produced by certain bacteria, fungi, and algae. It is an antifeedant in a number of plants. Cyanides are found in substantial amounts in certain seeds and fruit stones, e.g., those of bitter almonds, apricots, apples, and peaches. Chemical compounds that can release cyanide are known as cyanogenic compounds. In plants, cyanides are usually bound to sugar molecules in the form of cyanogenic glycosides and defend the plant against herbivores. Cassava roots (also called manioc), an important potato-like food grown in tropical countries (and the base from which tapioca is made), also contain cyanogenic glycosides.

The Madagascar bamboo Cathariostachys madagascariensis produces cyanide as a deterrent to grazing. In response, the golden bamboo lemur, which eats the bamboo, has developed a high tolerance to cyanide.

The hydrogenase enzymes contain cyanide ligands attached to iron in their active sites. The biosynthesis of cyanide in the NiFe hydrogenases proceeds from carbamoyl phosphate, which converts to cysteinyl thiocyanate, the CN⁻ donor.

Interstellar medium

The cyanide radical •CN has been identified in interstellar space. Cyanogen, (CN)₂, is used to measure the temperature of interstellar gas clouds.

Pyrolysis and combustion product

Hydrogen cyanide is produced by the combustion or pyrolysis of certain materials under oxygen-deficient conditions. For example, it can be detected in the exhaust of internal combustion engines and tobacco smoke. Certain plastics, especially those derived from acrylonitrile, release hydrogen cyanide when heated or burnt.

Organic derivatives

Main article: Nitriles

See also: Isocyanide

In IUPAC nomenclature, organic compounds that have a −C≡N functional group are called nitriles. An example of a nitrile is acetonitrile, CH₃−C≡N. Nitriles usually do not release cyanide ions. A functional group with a hydroxyl −OH and cyanide −CN bonded to the same carbon atom is called cyanohydrin (R₂C(OH)CN). Unlike nitriles, cyanohydrins do release poisonous hydrogen cyanide.

Reactions

Protonation

Cyanide is basic. The pK_a of hydrogen cyanide is 9.21. Thus, addition of acids stronger than hydrogen cyanide to solutions of cyanide salts releases hydrogen cyanide.

Hydrolysis

Cyanide is unstable in water, but the reaction is slow until about 170 °C. It undergoes hydrolysis to give ammonia and formate, which are far less toxic than cyanide:

CN⁻ + 2 H₂O → HCO−2 + NH₃

Cyanide hydrolase is an enzyme that catalyzes this reaction.

Alkylation

Because of the cyanide anion's high nucleophilicity, cyano groups are readily introduced into organic molecules by displacement of a halide group (e.g., the chloride on methyl chloride). In general, organic cyanides are called nitriles. In organic synthesis, cyanide is a C-1 synthon; i.e., it can be used to lengthen a carbon chain by one, while retaining the ability to be functionalized.

RX + CN⁻ → RCN + X⁻

Redox

The cyanide ion is a reductant and is oxidized by strong oxidizing agents such as molecular chlorine (Cl₂), hypochlorite (ClO⁻), and hydrogen peroxide (H₂O₂). These oxidizers are used to destroy cyanides in effluents from gold mining.

Metal complexation

The cyanide anion reacts with transition metals to form M-CN bonds. This reaction is the basis of cyanide's toxicity. The high affinities of metals for this anion can be attributed to its negative charge, compactness, and ability to engage in π-bonding.

Among the most important cyanide coordination compounds are the potassium ferrocyanide and the pigment Prussian blue, which are both essentially nontoxic due to the tight binding of the cyanides to a central iron atom. Prussian blue was first accidentally made around 1706, by heating substances containing iron and carbon and nitrogen, and other cyanides made subsequently (and named after it). Among its many uses, Prussian blue gives the blue color to blueprints, bluing, and cyanotypes.

Manufacture

Main article: Hydrogen cyanide § Production and synthesis

The principal process used to manufacture cyanides is the Andrussow process in which gaseous hydrogen cyanide is produced from methane and ammonia in the presence of oxygen and a platinum catalyst.

2 CH₄ + 2 NH₃ + 3 O₂ → 2 HCN + 6 H₂O

Sodium cyanide, the precursor to most cyanides, is produced by treating hydrogen cyanide with sodium hydroxide:

HCN + NaOH → NaCN + H₂O

Toxicity

Main article: Cyanide poisoning

Many cyanides are highly toxic. The cyanide anion is an inhibitor of the enzyme cytochrome c oxidase (also known as aa₃), the fourth complex of the electron transport chain found in the inner membrane of the mitochondria of eukaryotic cells. It attaches to the iron within this protein. The binding of cyanide to this enzyme prevents transport of electrons from cytochrome c to oxygen. As a result, the electron transport chain is disrupted, meaning that the cell can no longer aerobically produce ATP for energy. Tissues that depend highly on aerobic respiration, such as the central nervous system and the heart, are particularly affected. This is an example of histotoxic hypoxia.

The most hazardous compound is hydrogen cyanide, which is a gas and kills by inhalation. For this reason, an air respirator supplied by an external oxygen source must be worn when working with hydrogen cyanide. Hydrogen cyanide is produced by adding acid to a solution containing a cyanide salt. Alkaline solutions of cyanide are safer to use because they do not evolve hydrogen cyanide gas. Hydrogen cyanide may be produced in the combustion of polyurethanes; for this reason, polyurethanes are not recommended for use in domestic and aircraft furniture. Oral ingestion of a small quantity of solid cyanide or a cyanide solution of as little as 200 mg, or exposure to airborne cyanide of 270 ppm, is sufficient to cause death within minutes.

Organic nitriles do not readily release cyanide ions, and so have low toxicities. By contrast, compounds such as trimethylsilyl cyanide (CH₃)₃SiCN readily release HCN or the cyanide ion upon contact with water.

Antidote

Hydroxocobalamin reacts with cyanide to form cyanocobalamin, which can be safely eliminated by the kidneys. This method has the advantage of avoiding the formation of methemoglobin (see below). This antidote kit is sold under the brand name Cyanokit and was approved by the U.S. FDA in 2006.

An older cyanide antidote kit included administration of three substances: amyl nitrite pearls (administered by inhalation), sodium nitrite, and sodium thiosulfate. The goal of the antidote was to generate a large pool of ferric iron (Fe³⁺) to compete for cyanide with cytochrome a₃ (so that cyanide will bind to the antidote rather than the enzyme). The nitrites oxidize hemoglobin to methemoglobin, which competes with cytochrome oxidase for the cyanide ion. Cyanmethemoglobin is formed and the cytochrome oxidase enzyme is restored. The major mechanism to remove the cyanide from the body is by enzymatic conversion to thiocyanate by the mitochondrial enzyme rhodanese. Thiocyanate is a relatively non-toxic molecule and is excreted by the kidneys. To accelerate this detoxification, sodium thiosulfate is administered to provide a sulfur donor for rhodanese, needed in order to produce thiocyanate.

Sensitivity

Minimum risk levels (MRLs) may not protect for delayed health effects or health effects acquired following repeated sublethal exposure, such as hypersensitivity, asthma, or bronchitis. MRLs may be revised after sufficient data accumulates.

Applications

Mining

Main article: Gold cyanidation

Cyanide is mainly produced for the mining of silver and gold: It helps dissolve these metals allowing separation from the other solids. In the cyanide process, finely ground high-grade ore is mixed with the cyanide (at a ratio of about 1:500 parts NaCN to ore); low-grade ores are stacked into heaps and sprayed with a cyanide solution (at a ratio of about 1:1000 parts NaCN to ore). The precious metals are complexed by the cyanide anions to form soluble derivatives, e.g., [Ag(CN)₂]⁻ (dicyanoargentate(I)) and [Au(CN)₂]⁻ (dicyanoaurate(I)). Silver is less "noble" than gold and often occurs as the sulfide, in which case redox is not invoked (no O₂ is required). Instead, a displacement reaction occurs:

${\displaystyle {\text{Ag}}_2^{}\text{S}+4\text{NaCN}+{\text{H}}_2^{}\text{O}⟶2\text{Na}[\text{Ag}{(\text{CN})}_2^{}]+\text{NaSH}+\text{NaOH}}$

${\displaystyle 4\text{Au}+8\text{NaCN}+{\text{O}}_2^{}+2{\text{H}}_2^{}\text{O}⟶4\text{Na}[\text{Au}{(\text{CN})}_2^{}]+4\text{NaOH}}$

The "pregnant liquor" containing these ions is separated from the solids, which are discarded to a tailing pond or spent heap, the recoverable gold having been removed. The metal is recovered from the "pregnant solution" by reduction with zinc dust or by adsorption onto activated carbon. This process can result in environmental and health problems. A number of environmental disasters have followed the overflow of tailing ponds at gold mines. Cyanide contamination of waterways has resulted in numerous cases of human and aquatic species mortality.

Aqueous cyanide is hydrolyzed rapidly, especially in sunlight. It can mobilize some heavy metals such as mercury if present. Gold can also be associated with arsenopyrite (FeAsS), which is similar to iron pyrite (fool's gold), wherein half of the sulfur atoms are replaced by arsenic. Gold-containing arsenopyrite ores are similarly reactive toward inorganic cyanide.

Industrial organic chemistry

The second major application of alkali metal cyanides (after mining) is in the production of CN-containing compounds, usually nitriles. Acyl cyanides are produced from acyl chlorides and cyanide. Cyanogen, cyanogen chloride, and the trimer cyanuric chloride are derived from alkali metal cyanides.

Medical uses

The cyanide compound sodium nitroprusside is used mainly in clinical chemistry to measure urine ketone bodies mainly as a follow-up to diabetic patients. On occasion, it is used in emergency medical situations to produce a rapid decrease in blood pressure in humans; it is also used as a vasodilator in vascular research. The cobalt in artificial vitamin B₁₂ contains a cyanide ligand as an artifact of the purification process; this must be removed by the body before the vitamin molecule can be activated for biochemical use. During World War I, a copper cyanide compound was briefly used by Japanese physicians for the treatment of tuberculosis and leprosy.

Illegal fishing and poaching

Main article: Cyanide fishing

Cyanides are illegally used to capture live fish near coral reefs for the aquarium and seafood markets. The practice is controversial, dangerous, and damaging but is driven by the lucrative exotic fish market.

Poachers in Africa have been known to use cyanide to poison waterholes, to kill elephants for their ivory.

Pest control

M44 cyanide devices are used in the United States to kill coyotes and other canids. Cyanide is also used for pest control in New Zealand, particularly for possums, an introduced marsupial that threatens the conservation of native species and spreads tuberculosis amongst cattle. Possums can become bait shy but the use of pellets containing the cyanide reduces bait shyness. Cyanide has been known to kill native birds, including the endangered kiwi. Cyanide is also effective for controlling the dama wallaby, another introduced marsupial pest in New Zealand. A licence is required to store, handle and use cyanide in New Zealand.

Cyanides are used as insecticides for fumigating ships. Cyanide salts are used for killing ants, and have in some places been used as rat poison (the less toxic poison arsenic is more common).

Niche uses

Potassium ferrocyanide is used to achieve a blue color on cast bronze sculptures during the final finishing stage of the sculpture. On its own, it will produce a very dark shade of blue and is often mixed with other chemicals to achieve the desired tint and hue. It is applied using a torch and paint brush while wearing the standard safety equipment used for any patina application: rubber gloves, safety glasses, and a respirator. The actual amount of cyanide in the mixture varies according to the recipes used by each foundry.

Cyanide is also used in jewelry-making and certain kinds of photography such as sepia toning.

Although usually thought to be toxic, cyanide and cyanohydrins increase germination in various plant species.

Human poisoning

Main article: Cyanide poisoning

Deliberate cyanide poisoning of humans has occurred many times throughout history. Common salts such as sodium cyanide are involatile but water-soluble, so are poisonous by ingestion. Hydrogen cyanide is a gas, making it more indiscriminately dangerous, however it is lighter than air and rapidly disperses up into the atmosphere, which makes it ineffective as a chemical weapon. Poisoning by hydrogen cyanide is more effective in an enclosed space, such as a gas chamber. Most significantly, hydrogen cyanide released from pellets of Zyklon-B was used extensively in the extermination camps of the Holocaust.

Food additive

Because of the high stability of their complexation with iron, ferrocyanides (Sodium ferrocyanide E535, Potassium ferrocyanide E536, and Calcium ferrocyanide E538) do not decompose to lethal levels in the human body and are used in the food industry as, e.g., an anticaking agent in table salt.

Chemical tests for cyanide

Cyanide is quantified by potentiometric titration, a method widely used in gold mining. It can also be determined by titration with silver ion. Some analyses begin with an air-purge of an acidified boiling solution, sweeping the vapors into a basic absorber solution. The cyanide salt absorbed in the basic solution is then analyzed.

Qualitative tests

Because of the notorious toxicity of cyanide, many methods have been investigated. Benzidine gives a blue coloration in the presence of ferricyanide. Iron(II) sulfate added to a solution of cyanide, such as the filtrate from the sodium fusion test, gives prussian blue. A solution of para-benzoquinone in DMSO reacts with inorganic cyanide to form a cyanophenol, which is fluorescent. Illumination with a UV light gives a green/blue glow if the test is positive.

Virtue ethics

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Virtue_ethics 

Virtue ethics (also aretaic ethics, from Greek ἀρετή [aretḗ]) is an approach to ethics that treats virtue as central.

Virtue ethics is usually contrasted with two other major approaches in ethics, consequentialism and deontology, which make the goodness of outcomes of an action (consequentialism) and the concept of moral duty (deontology) central. While virtue ethics does not necessarily deny the importance to ethics of goodness of states of affairs or of moral duties, it emphasizes virtue, and sometimes other concepts, like eudaimonia, to an extent that other ethics theories do not.

Key concepts

Virtue and vice

Main articles: Virtue and Moral character

In virtue ethics, a virtue is a disposition to think, feel, and act well in some domain of life. Similarly, a vice is a disposition to think, feel, and act poorly. Virtues are not everyday habits; they are character traits, in the sense that they are central to someone’s personality and what they are like as a person. A virtue is a trait that promotes or exhibits human excellence in the person who exhibits it, and a vice is one that impedes human excellence in the person who exhibits it.

In ancient Greek and modern eudaimonistic virtue ethics, virtues and vices are complex dispositions that involve both affective and intellectual components. That is, they are dispositions that involve both being able to reason well about what the right thing to do is (see below on phronesis), and also engaging our emotions and feelings correctly.

For example, a generous person can reason well about when to help people, and such a person also helps people with pleasure and without conflict. In this, virtuous people are contrasted not only with vicious people (who reason poorly about what to do and are emotionally attached to the wrong things) and with the incontinent (who are tempted by their feelings into doing the wrong thing even though they know what is right), but also with the merely continent (whose emotions tempt them toward doing the wrong thing but whose strength of will lets them do what they know is right).

Phronesis and eudaimonia

Phronesis (φρόνησις; prudence, practical virtue, or practical wisdom) is an acquired trait that enables its possessor to identify the best thing to do in any given situation. Unlike theoretical wisdom, practical reason results in action or decision. As John McDowell puts it, practical wisdom involves a "perceptual sensitivity" to what a situation requires.

Eudaimonia (εὐδαιμονία) is a state variously translated from Greek as 'well-being', 'happiness', 'blessedness', and in the context of virtue ethics, 'human flourishing'. Eudaimonia in this sense is not a subjective, but an objective, state. It characterizes the well-lived life.

According to Aristotle, the most prominent exponent of eudaimonia in the Western philosophical tradition, eudaimonia defines the goal of human life. It consists of exercising the characteristic human quality—reason—as the soul's most proper and nourishing activity. In his Nicomachean Ethics, Aristotle, like Plato before him, argued that the pursuit of eudaimonia is an "activity of the soul in accordance with perfect virtue", which further could only properly be exercised in the characteristic human community—the polis or city-state.

Although eudaimonia was first popularized by Aristotle, it now belongs to the tradition of virtue theories generally. For the virtue theorist, eudaimonia describes that state achieved by the person who lives the proper human life, an outcome that can be reached by practicing the virtues. A virtue is a habit or quality that allows the bearer to succeed at his, her, or its purpose. The virtue of a knife, for example, is sharpness; among the virtues of a racehorse is speed. Thus, to identify the virtues for human beings, one must have an account of what is the human purpose.

History of virtue

Like much of the Western tradition, virtue theory originated in ancient Greek philosophy.

Virtue ethics began with Socrates, and was subsequently developed further by Plato, Aristotle, and the Stoics. Virtue ethics refers to a collection of normative ethical philosophies that place an emphasis on being rather than doing. Another way to say this is that virtue ethics concentrates on the character of the individual, rather than the actions (or consequences thereof) of the individual. There is debate among adherents of virtue ethics concerning what specific virtues are praiseworthy. However, most theorists agree that ethics is demonstrated by the practice of virtues.

Plato and Aristotle's treatments of virtues are not the same. Plato believes virtue is effectively an end to be sought, for which a friend might be a useful means. Aristotle states that the virtues function more as means to safeguard human relations, particularly authentic friendship, without which one's quest for happiness is frustrated.

Discussion of what were known as the four cardinal virtues—wisdom, justice, fortitude, and temperance—can be found in Plato's Republic. The virtues also figure prominently in Aristotle's ethical theory found in Nicomachean Ethics.

Virtue theory was inserted into the study of history by moralistic historians such as Livy, Plutarch, and Tacitus. The Greek idea of the virtues was passed on in Roman philosophy through Cicero and later incorporated into Christian moral theology by Ambrose of Milan. During the scholastic period, the most comprehensive consideration of the virtues from a theological perspective was provided by Thomas Aquinas in his Summa Theologiae and his Commentaries on the Nicomachean Ethics. After the Reformation, Aristotle's Nicomachean Ethics continued to be the main authority for the discipline of ethics at Protestant universities until the late seventeenth century, with over fifty Protestant commentaries published on the Nicomachean Ethics before 1682.

Though the tradition receded into the background of European philosophical thought in the past few centuries, the term "virtue" remained current during this period, and in fact appears prominently in the tradition of classical republicanism or classical liberalism. This tradition was prominent in the intellectual life of 16th-century Italy, as well as 17th- and 18th-century Britain and America; indeed the term "virtue" appears frequently in the work of Niccolò Machiavelli, David Hume, the republicans of the English Civil War period, the 18th-century English Whigs, and the prominent figures among the Scottish Enlightenment and the American Founding Fathers.

Contemporary "aretaic turn"

Although some Enlightenment philosophers (e.g. Hume) continued to emphasise the virtues, with the ascendancy of utilitarianism and deontological ethics, virtue theory moved to the margins of Western philosophy. The contemporary revival of virtue theory is frequently traced to the philosopher Elizabeth Anscombe's 1958 essay "Modern Moral Philosophy". Following this:

• In the 1976 paper "The Schizophrenia of Modern Ethical Theories", Michael Stocker summarises the main aretaic criticisms of deontological and consequentialist ethics.
• Philosopher, psychologist, and encyclopedist Mortimer Adler appealed to Aristotelian ethics, and the virtue theory of happiness or eudaimonia throughout his published work.
• Philippa Foot, published a collection of essays in 1978 entitled Virtues and Vices.
• Alasdair MacIntyre made an effort to reconstruct a virtue-based theory in dialogue with the problems of modern and postmodern thought; his works include After Virtue and Three Rival Versions of Moral Enquiry.
• Paul Ricoeur accorded an important place to Aristotelian teleological ethics in his hermeneutical phenomenology of the subject, most notably in his book Oneself as Another.
• Theologian Stanley Hauerwas found the language of virtue helpful in his own project.
• Rosalind Hursthouse published On Virtue Ethics.
• Roger Crisp and Michael Slote edited a collection of important essays titled Virtue Ethics.
• Martha Nussbaum and Amartya Sen employed virtue theory in theorising the capability approach to international development.
• Julia Annas wrote The Morality of Happiness (1993).
• Lawrence C. Becker identified current virtue theory with Greek Stoicism in A New Stoicism. (1998).
• Psychologist Martin Seligman drew on classical virtue ethics in conceptualizing positive psychology.
• Psychologist Daniel Goleman opens his book on Emotional Intelligence with a challenge from Aristotle's Nicomachean Ethics.
• Michael Sandel discusses Aristotelian ethics to support his ethical theory of justice in his book Justice: What's the Right Thing to Do?

The aretaic turn in moral philosophy is paralleled by analogous developments in other philosophical disciplines. One of these is epistemology, where a distinctive virtue epistemology was developed by Linda Zagzebski and others. In political theory, there has been discussion of "virtue politics", and in legal theory, there is a small but growing body of literature on virtue jurisprudence. The aretaic turn also exists in American constitutional theory, where proponents argue for an emphasis on virtue and vice of constitutional adjudicators.

Aretaic approaches to morality, epistemology, and jurisprudence have been the subject of intense debates. One criticism focuses on the problem of guidance; opponents, such as Robert Louden in his article "Some Vices of Virtue Ethics", question whether the idea of a virtuous moral actor, believer, or judge can provide the guidance necessary for action, belief formation, or the resolution of legal disputes.

Lists of virtues

There are several lists of virtues. Socrates argued that virtue is knowledge, which suggests that there is really only one virtue. The Stoics identified four cardinal virtues: wisdom, justice, courage, and temperance. Wisdom is subdivided into good sense, good calculation, quick-wittedness, discretion, and resourcefulness. Justice is subdivided into piety, honesty, equity, and fair dealing. Courage is subdivided into endurance, confidence, high-mindedness, cheerfulness, and industriousness. Temperance or moderation is subdivided into good discipline, seemliness, modesty, and self-control.

John McDowell defends this conception. He argues that virtue is a "perceptual capacity" to identify how one ought to act, and that all particular virtues are merely "specialized sensitivities" to a range of reasons for acting.

Aristotle's list

Aristotle identifies approximately 18 virtues that enable a person to perform their human function well. He distinguished virtues pertaining to emotion and desire from those relating to the mind. The first he calls moral virtues, and the second intellectual virtues (though both are "moral" in the modern sense of the word).

Moral virtues

Aristotle suggested that each moral virtue was a mean (see golden mean) between two corresponding vices, one of excess and one of deficiency. Each intellectual virtue is a mental skill or habit by which the mind arrives at truth, affirming what is or denying what is not. In the Nicomachean Ethics he discusses about 11 moral virtues:

SPHERE OF ACTION OR FEELING	EXCESS	MEAN: MORAL VIRTUE	DEFICIENCY
Fear and confidence	Rashness	Courage in the face of fear	Cowardice
Pleasure and pain	Licentiousness/self-indulgence	Temperance in the face of pleasure and pain	Insensibility
Getting and spending (minor)	Prodigality	Liberality with wealth and possessions	Illiberality/meanness
Getting and spending (major)	Vulgarity/tastelessness	Magnificence with great wealth and possessions	Pettiness/stinginess
Honour and dishonour (major)	Vanity	Magnanimity with great honors	Pusillanimity
Honour and dishonour (minor)	Ambition/empty vanity	Proper ambition with normal honors	Unambitiousness/undue humility
Anger	Irascibility	Patience/good temper	Lack of spirit/unirascibility
Self-expression	Boastfulness	Truthfulness with self-expression	Understatement/mock modesty
Conversation	Buffoonery	Wittiness in conversation	Boorishness
Social conduct	Obsequiousness	Friendliness in social conduct	Cantankerousness
Shame	Shyness	Modesty in the face of shame or shamelessness	Shamelessness
Indignation	Envy	Righteous indignation in the face of injury	Malicious enjoyment/spitefulness

Intellectual virtues

1. Nous (intelligence), which apprehends fundamental truths (such as definitions, self-evident principles)
2. Episteme (science), which is skill with inferential reasoning (such as proofs, syllogisms, demonstrations)
3. Sophia (theoretical wisdom), which combines fundamental truths with valid, necessary inferences to reason well about unchanging truths.

Aristotle also mentions several other traits:

• Gnome (good sense) – passing judgment, "sympathetic understanding"
• Synesis (understanding) – comprehending what others say, does not issue commands
• Phronesis (practical wisdom) – knowledge of what to do, knowledge of changing truths, issues commands
• Techne (art, craftsmanship)

Aristotle's list is not the only list, however. As Alasdair MacIntyre observed in After Virtue, thinkers as diverse as Homer, the authors of the New Testament, Thomas Aquinas, and Benjamin Franklin have all proposed lists.

Criticisms

Regarding which are the most important virtues, Aristotle proposed the following nine: wisdom; prudence; justice; fortitude; courage; liberality; magnificence; magnanimity; temperance. In contrast, philosopher Walter Kaufmann proposed as the four cardinal virtues ambition/humility, love, courage, and honesty.

Regarding virtues supposedly applicable to women, many would have once considered a virtuous woman to be quiet, servile, and industrious. This conception of female virtue no longer holds true in many modern societies. Proponents of virtue theory sometimes respond to this objection by arguing that a central feature of a virtue is its universal applicability. In other words, any character trait defined as a virtue must reasonably be universally regarded as a virtue for all people. According to this view, it is inconsistent to claim, for example, servility as a female virtue, while at the same time not proposing it as a male one.

Other proponents of virtue theory, notably Alasdair MacIntyre, respond to this objection by arguing that any account of the virtues must indeed be generated out of the community in which those virtues are to be practiced: the very word ethics implies ethos. That is to say that the virtues are, and necessarily must be, grounded in a particular time and place. What counts as a virtue in 4th-century BCE Athens would be a ludicrous guide to proper behaviour in 21st-century CE Toronto and vice versa. To take this view does not necessarily commit one to the argument that accounts of the virtues must therefore be static: moral activity—that is, attempts to contemplate and practice the virtues—can provide the cultural resources that allow people to change, albeit slowly, the ethos of their own societies.

MacIntyre appears to take this position in his seminal work on virtue ethics, After Virtue. One might cite (though MacIntyre does not) the rapid emergence of abolitionist thought in the slave-holding societies of the 18th-century Atlantic world as an example of this sort of change: over a relatively short period of time, perhaps 1760 to 1800, in Britain, France, and British America, slave-holding, previously thought to be morally neutral or even virtuous, rapidly became seen as vicious among wide swathes of society. While the emergence of abolitionist thought derived from many sources, the work of David Brion Davis, among others, established that one source was the rapid, internal evolution of moral theory among certain sectors of these societies, notably the Quakers.

Another objection to virtue theory is that virtue ethics does not focus on what sorts of actions are morally permitted and which ones are not, but rather on what sort of qualities someone ought to foster in order to become a good person. In other words, while some virtue theorists may not condemn, for example, murder as an inherently immoral or impermissible sort of action, they may argue that someone who commits a murder is severely lacking in several important virtues, such as compassion and fairness. Still, antagonists of the theory often object that this particular feature of the theory makes virtue ethics useless as a universal norm of acceptable conduct suitable as a base for legislation. Some virtue theorists concede this point, but respond by opposing the very notion of legitimate legislative authority instead, effectively advocating some form of anarchism as the political ideal. Others argue that laws should be made by virtuous legislators. Still, others argue that it is possible to base a judicial system on the moral notion of virtues rather than rules. Aristotle himself saw his Nicomachean Ethics as a prequel for his Politics and felt that the point of politics was to create the fertile soil for a virtuous citizenry to develop in, and that one purpose of virtue was that it helps you to contribute to a healthy polis.

Some virtue theorists might respond to this overall objection with the notion of a "bad act" also being an act characteristic of vice. That is to say that those acts that do not aim at virtue, or that stray from virtue, would constitute our conception of "bad behavior". Although not all virtue ethicists agree to this notion, this is one way the virtue ethicist can re-introduce the concept of the "morally impermissible". One could raise an objection that he is committing an argument from ignorance by postulating that what is not virtuous is unvirtuous. In other words, just because an action or person 'lacks of evidence' for virtue does not, all else constant, imply that said action or person is unvirtuous.

Subsumed in deontology and utilitarianism

Martha Nussbaum suggested that while virtue ethics is often considered to be anti-Enlightenment, "suspicious of theory and respectful of the wisdom embodied in local practices", it is actually neither fundamentally distinct from, nor does it qualify as a rival approach to deontology and utilitarianism. She argues that philosophers from these two Enlightenment traditions often include theories of virtue. She pointed out that Kant's "Doctrine of Virtue" (in The Metaphysics of Morals) "covers most of the same topics as do classical Greek theories", "that he offers a general account of virtue, in terms of the strength of the will in overcoming wayward and selfish inclinations; that he offers detailed analyses of standard virtues such as courage and self-control, and of vices, such as avarice, mendacity, servility, and pride; that, although in general, he portrays inclination as inimical to virtue, he also recognizes that sympathetic inclinations offer crucial support to virtue, and urges their deliberate cultivation."

Nussbaum also points to considerations of virtue by utilitarians such as Henry Sidgwick (The Methods of Ethics), Jeremy Bentham (The Principles of Morals and Legislation), and John Stuart Mill, who writes of moral development as part of an argument for the moral equality of women (The Subjection of Women). She argues that contemporary virtue ethicists such as Alasdair MacIntyre, Bernard Williams, Philippa Foot, and John McDowell have few points of agreement and that the common core of their work does not represent a break from Kant.

Kantian critique

Immanuel Kant's position on virtue ethics is contested. Those who argue that Kantian deontology conflicts with virtue ethics include Alasdair MacIntyre, Philippa Foot, and Bernard Williams. In the Groundwork of the Metaphysics of Morals and the Critique of Practical Reason, Immanuel Kant offers many different criticisms of ethical frameworks and against moral theories before him.^{[citation needed]} Kant rarely mentioned Aristotle by name but did not exclude his moral philosophy of virtue ethics from his critique. Many Kantian arguments against virtue ethics claim that virtue ethics is inconsistent, or sometimes that it isn't a real moral theory at all.

Utopianism and pluralism

Robert B. Louden criticizes virtue ethics on the basis that it promotes a form of unsustainable utopianism. Trying to arrive at a single set of virtues is immensely difficult in contemporary societies as, according to Louden, they contain "more ethnic, religious, and class groups than did the moral community which Aristotle theorized about" with each of these groups having "not only its own interests but its own set of virtues as well". Louden notes in passing that MacIntyre, a supporter of virtue-based ethics, has grappled with this in After Virtue but that ethics cannot dispense with building rules around acts and rely only on discussing the moral character of persons.

Topics in virtue ethics

Virtue ethics as a category

Virtue contrasts with deontological and consequentialist ethics (the three being together the most predominant contemporary normative ethical theories).

Deontological ethics, sometimes referred to as duty ethics, places the emphasis on adhering to ethical principles or duties. How these duties are defined, however, is often a point of contention and debate in deontological ethics. One predominant rule scheme used by deontologists is divine command theory. Deontology also depends upon meta-ethical realism, in that it postulates the existence of moral absolutes that make an action moral, regardless of circumstances. Immanuel Kant is considered one of the foremost theorists of deontological ethics.

The next predominant school of thought in normative ethics is consequentialism. While deontology places the emphasis on doing one's duty, consequentialism bases the morality of an action upon its outcome. Instead of saying that one has a moral duty to abstain from murder, a consequentialist would say that we should abstain from murder because it causes undesirable effects. The main contention here is what outcomes should/can be identified as objectively desirable.

The greatest happiness principle of John Stuart Mill is a commonly adopted criteria for what is objectively desirable. Mill asserts that the desirability of an action is the net amount of happiness it brings, the number of people it brings it to, and the duration of the happiness. He tries to delineate classes of happiness, some preferable to others, but there is a great deal of difficulty in classifying such concepts.

Further information: Utilitarianism, Utilitarianism (book), and On Liberty

Virtue ethics differs from both deontology and consequentialism as it focuses on being over doing.^{[clarification needed]} A virtue ethicist identifies virtues, desirable characteristics, that an excellent person embodies. Exhibiting these virtues is the aim of ethics, and one's actions are a mere reflection of one's virtues. To the virtue philosopher, action cannot be used as a demarcation of morality, because a virtue encompasses more than just a simple selection of action. Instead, a virtue is a way of being that leads the person exhibiting the virtue to make certain "virtuous" types of choices consistently in each situation. There is a great deal of disagreement within virtue ethics over what are virtues and what are not. There are also difficulties in identifying what is the "virtuous" action to take in all circumstances, and how to define a virtue.

Consequentialist and deontological theories often still employ the term virtue, but in a restricted sense, namely as a tendency or disposition to adhere to the system's principles or rules. These very different senses of what constitutes virtue, hidden behind the same word, are a potential source of confusion. This disagreement over the meaning of virtue points to a larger conflict between virtue theory and its philosophical rivals. A system of virtue theory is only intelligible if it is teleological: that is, if it includes an account of the purpose (telos) of human life, or in popular language, the meaning of life.^{[citation needed]} Obviously, strong claims about the purpose of human life, or of what the good life for human beings is, will be controversial. Virtue theory's necessary commitment to a teleological account of human life thus puts the tradition in tension with other dominant approaches to normative ethics, which, because they focus on actions, do not bear this burden.

Virtue ethics mainly deals with the honesty and morality of a person. It states that practicing good habits such as honesty, generosity makes a moral and virtuous person. It guides a person without specific rules for resolving the ethical complexity.

Virtue and politics

Virtue theory emphasises Aristotle's belief in the polis as the acme of political organisation, and the role of the virtues in enabling human beings to flourish in that environment. Classical republicanism in contrast emphasises Tacitus' concern that power and luxury can corrupt individuals and destroy liberty, as Tacitus perceived in the transformation of the Roman Republic into the Roman Empire; virtue for classical republicans is a shield against this sort of corruption and a means to preserve the good life one has, rather than a means by which to achieve the good life one does not yet have. Another way to put the distinction between the two traditions is that virtue ethics relies on Aristotle's fundamental distinction between the human-being-as-he-is from the human-being-as-he-should-be, while classical republicanism relies on the Tacitean distinction of the risk-of-becoming.

Virtue ethics has a number of contemporary applications.

Social and political philosophy

Within the field of social ethics, Deirdre McCloskey argues that virtue ethics can provide a basis for a balanced approach to understanding capitalism and capitalist societies.

Education

Within the field of philosophy of education, James Page argues that virtue ethics can provide a rationale and foundation for peace education.

Health care and medical ethics

Thomas Alured Faunce argued that whistleblowing in the healthcare setting would be more respected within clinical governance pathways if it had a firmer academic foundation in virtue ethics. He called for whistleblowing to be expressly supported in the UNESCO Universal Declaration on Bioethics and Human Rights. Barry Schwartz argues that "practical wisdom" is an antidote to much of the inefficient and inhumane bureaucracy of modern health care systems.

Technology and the virtues

In her book Technology and the Virtues, Shannon Vallor proposed a series of 'technomoral' virtues that people need to cultivate in order to flourish in our socio-technological world: Honesty (Respecting Truth), Self-control (Becoming the Author of Our Desires), Humility (Knowing What We Do Not Know), Justice (Upholding Rightness), Courage (Intelligent Fear and Hope), Empathy (Compassionate Concern for Others), Care (Loving Service to Others), Civility (Making Common Cause), Flexibility (Skillful Adaptation to Change), Perspective (Holding on to the Moral Whole), and Magnanimity (Moral Leadership and Nobility of Spirit).

Electronic paper

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Electronic_paper

Many e-readers, devices meant to replace traditional books, utilize electronic paper for their displays in order to further resemble paper books; one such example is the Kindle series by Amazon.

Electronic paper, also known as electronic ink (e-ink) or intelligent paper, is a display device that mimics the appearance of ordinary ink on paper. Unlike conventional flat panel displays that emit light, an electronic paper display reflects ambient light, like paper. This may make them more comfortable to read, and provide a wider viewing angle than most light-emitting displays. The contrast ratio in electronic displays available as of 2008 approaches newspaper, and newly developed displays are slightly better. An ideal e-paper display can be read in direct sunlight without the image appearing to fade.

Technologies include Gyricon, electrophoretics, electrowetting, interferometry, and plasmonics. Many electronic paper technologies hold static text and images indefinitely without electricity. Flexible electronic paper uses plastic substrates and plastic electronics for the display backplane. Applications of electronic visual displays include electronic shelf labels and digital signage, bus station time tables, electronic billboards, smartphone displays, and e-readers able to display digital versions of books and magazines.

Technologies

Gyricon

Main article: Gyricon

Electronic paper was first developed in the 1970s by Nick Sheridon at Xerox's Palo Alto Research Center. The first electronic paper, called Gyricon, consisted of polyethylene spheres between 75 and 106 micrometers across. Each sphere is a Janus particle composed of negatively charged black plastic on one side and positively charged white plastic on the other (each bead is thus a dipole). The spheres are embedded in a transparent silicone sheet, with each sphere suspended in a bubble of oil so that it can rotate freely. The polarity of the voltage applied to each pair of electrodes then determines whether the white or black side is face-up, thus giving the pixel a white or black appearance. At the FPD 2008 exhibition, Japanese company Soken demonstrated a wall with electronic wall-paper using this technology. In 2007, the Estonian company Visitret Displays was developing this kind of display using polyvinylidene fluoride (PVDF) as the material for the spheres, dramatically improving the video speed and decreasing the control voltage needed.

Electrophoretic

Appearance of pixels

An electrophoretic display (EPD) forms images by rearranging charged pigment particles with an applied electric field. In the simplest implementation of an EPD, titanium dioxide (titania) particles approximately one micrometer in diameter are dispersed in a hydrocarbon oil. A dark-colored dye is also added to the oil, along with surfactants and charging agents that cause the particles to take on an electric charge. This mixture is placed between two parallel, conductive plates separated by a gap of 10 to 100 micrometres. When a voltage is applied across the two plates, the particles migrate electrophoretically to the plate that bears the opposite charge from that on the particles. When the particles are located at the front (viewing) side of the display, it appears white, because the light is scattered back to the viewer by the high-index titania particles. When the particles are located at the rear side of the display, it appears dark, because the light is absorbed by the colored dye. If the rear electrode is divided into a number of small picture elements (pixels), then an image can be formed by applying the appropriate voltage to each region of the display to create a pattern of reflecting and absorbing regions.

EPDs are typically addressed using MOSFET-based thin-film transistor (TFT) technology. TFTs are often used to form a high-density image in an EPD. A common application for TFT-based EPDs are e-readers. Electrophoretic displays are considered prime examples of the electronic paper category, because of their paper-like appearance and low power consumption. Examples of commercial electrophoretic displays include the high-resolution active matrix displays used in the Amazon Kindle, Barnes & Noble Nook, Sony Reader, Kobo eReader, and iRex iLiad e-readers. These displays are constructed from an electrophoretic imaging film manufactured by E Ink Corporation. A mobile phone that used the technology is the Motorola Fone.

Electrophoretic Display technology has also been developed by SiPix and Bridgestone/Delta. SiPix is now part of E Ink Corporation. The SiPix design uses a flexible 0.15 mm Microcup architecture, instead of E Ink's 0.04 mm diameter microcapsules. Bridgestone Corp.'s Advanced Materials Division cooperated with Delta Optoelectronics Inc. in developing Quick Response Liquid Powder Display technology.

Electrophoretic displays can be manufactured using the Electronics on Plastic by Laser Release (EPLaR) process, developed by Philips Research, to enable existing AM-LCD manufacturing plants to create flexible plastic displays.

Microencapsulated electrophoretic display

Scheme of an electrophoretic display

Scheme of an electrophoretic display using color filters

Macro photograph of Kindle 3 screen; microcapsules are evident at full size.

In the 1990s another type of electronic ink based on a microencapsulated electrophoretic display was conceived and prototyped by a team of undergraduates at MIT as described in their Nature paper. J.D. Albert, Barrett Comiskey, Joseph Jacobson, Jeremy Rubin and Russ Wilcox co-founded E Ink Corporation in 1997 to commercialize the technology. E Ink subsequently formed a partnership with Philips Components two years later to develop and market the technology. In 2005, Philips sold the electronic paper business as well as its related patents to Prime View International.

"It has for many years been an ambition of researchers in display media to create a flexible low-cost system that is the electronic analog of paper. In this context, microparticle-based displays have long intrigued researchers. Switchable contrast in such displays is achieved by the electromigration of highly scattering or absorbing microparticles (in the size range 0.1–5 μm), quite distinct from the molecular-scale properties that govern the behavior of the more familiar liquid-crystal displays. Micro-particle-based displays possess intrinsic bistability, exhibit extremely low power d.c. field addressing and have demonstrated high contrast and reflectivity. These features, combined with a near-lambertian viewing characteristic, result in an 'ink on paper' look. But such displays have to date suffered from short lifetimes and difficulty in manufacture. Here we report the synthesis of an electrophoretic ink based on the microencapsulation of an electrophoretic dispersion. The use of a microencapsulated electrophoretic medium solves the lifetime issues and permits the fabrication of a bistable electronic display solely by means of printing. This system may satisfy the practical requirements of electronic paper."

This used tiny microcapsules filled with electrically charged white particles suspended in a colored oil. In early versions, the underlying circuitry controlled whether the white particles were at the top of the capsule (so it looked white to the viewer) or at the bottom of the capsule (so the viewer saw the color of the oil). This was essentially a reintroduction of the well-known electrophoretic display technology, but microcapsules meant the display could be made on flexible plastic sheets instead of glass. One early version of the electronic paper consists of a sheet of very small transparent capsules, each about 40 micrometers across. Each capsule contains an oily solution containing black dye (the electronic ink), with numerous white titanium dioxide particles suspended within. The particles are slightly negatively charged, and each one is naturally white. The screen holds microcapsules in a layer of liquid polymer, sandwiched between two arrays of electrodes, the upper of which is transparent. The two arrays are aligned to divide the sheet into pixels, and each pixel corresponds to a pair of electrodes situated on either side of the sheet. The sheet is laminated with transparent plastic for protection, resulting in an overall thickness of 80 micrometers, or twice that of ordinary paper. The network of electrodes connects to display circuitry, which turns the electronic ink 'on' and 'off' at specific pixels by applying a voltage to specific electrode pairs. A negative charge to the surface electrode repels the particles to the bottom of local capsules, forcing the black dye to the surface and turning the pixel black. Reversing the voltage has the opposite effect. It forces the particles to the surface, turning the pixel white. A more recent implementation of this concept requires only one layer of electrodes beneath the microcapsules. These are commercially referred to as Active Matrix Electrophoretic Displays (AMEPD).

Electrowetting

Main article: Electrowetting

Electrowetting display (EWD) is based on controlling the shape of a confined water/oil interface by an applied voltage. With no voltage applied, the (colored) oil forms a flat film between the water and a hydrophobic (water-repellent) insulating coating of an electrode, resulting in a colored pixel. When a voltage is applied between the electrode and the water, the interfacial tension between the water and the coating changes. As a result, the stacked state is no longer stable, causing the water to move the oil aside. This makes a partly transparent pixel, or, if a reflective white surface is under the switchable element, a white pixel. Because of the small pixel size, the user only experiences the average reflection, which provides a high-brightness, high-contrast switchable element.

Displays based on electrowetting provide several attractive features. The switching between white and colored reflection is fast enough to display video content. It is a low-power, low-voltage technology, and displays based on the effect can be made flat and thin. The reflectivity and contrast are better than or equal to other reflective display types and approach the visual qualities of paper. In addition, the technology offers a unique path toward high-brightness full-color displays, leading to displays that are four times brighter than reflective LCDs and twice as bright as other emerging technologies. Instead of using red, green, and blue (RGB) filters or alternating segments of the three primary colors, which effectively result in only one-third of the display reflecting light in the desired color, electrowetting allows for a system in which one sub-pixel can switch two different colors independently.

This results in the availability of two-thirds of the display area to reflect light in any desired color. This is achieved by building up a pixel with a stack of two independently controllable colored oil films plus a color filter.

The colors are cyan, magenta, and yellow, which is a subtractive system, comparable to the principle used in inkjet printing. Compared to LCD, brightness is gained because no polarisers are required.

Electrofluidic

Electrofluidic display is a variation of an electrowetting display that place an aqueous pigment dispersion inside a tiny reservoir. The reservoir comprises less than 5-10% of the viewable pixel area and therefore the pigment is substantially hidden from view. Voltage is used to electromechanically pull the pigment out of the reservoir and spread it as a film directly behind the viewing substrate. As a result, the display takes on color and brightness similar to that of conventional pigments printed on paper. When voltage is removed liquid surface tension causes the pigment dispersion to rapidly recoil into the reservoir. The technology can potentially provide greater than 85% white state reflectance for electronic paper.

The core technology was invented at the Novel Devices Laboratory at the University of Cincinnati and there are working prototypes developed by collaboration with Sun Chemical, Polymer Vision and Gamma Dynamics.

It has a wide margin in critical aspects such as brightness, color saturation and response time. Because the optically active layer can be less than 15 micrometres thick, there is strong potential for rollable displays.

Interferometric modulator (Mirasol)

Main article: Interferometric modulator display

The technology used in electronic visual displays that can create various colors via interference of reflected light. The color is selected with an electrically switched light modulator comprising a microscopic cavity that is switched on and off using driver integrated circuits similar to those used to address liquid-crystal displays (LCD).

Plasmonic electronic display

Plasmonic nanostructures with conductive polymers have also been suggested as one kind of electronic paper. The material has two parts. The first part is a highly reflective metasurface made by metal-insulator-metal films tens of nanometers in thickness including nanoscale holes. The metasurfaces can reflect different colors depending on the thickness of the insulator. The standard RGB color schema can be used as pixels for full-color displays. The second part is a polymer with optical absorption controllable by an electrochemical potential. After growing the polymer on the plasmonic metasurfaces, the reflection of the metasurfaces can be modulated by the applied voltage. This technology presents broad range colors, high polarization-independent reflection (>50 %), strong contrast (>30 %), the fast response time (hundreds of ms), and long-term stability. In addition, it has ultralow power consumption (< 0.5 mW/cm2) and potential for high resolution (>10000 dpi). Since the ultrathin metasurfaces are flexible and the polymer is soft, the whole system can be bent. Desired future improvements for this technology include bistability, cheaper materials and implementation with TFT arrays.

Other technologies

Other research efforts into e-paper have involved using organic transistors embedded into flexible substrates, including attempts to build them into conventional paper. Simple color e-paper consists of a thin colored optical filter added to the monochrome technology described above. The array of pixels is divided into triads, typically consisting of the standard cyan, magenta and yellow, in the same way as CRT monitors (although using subtractive primary colors as opposed to additive primary colors). The display is then controlled like any other electronic color display.

History

E Ink Corporation of E Ink Holdings Inc. released the first colored E Ink displays to be used in a marketed product. The Ectaco jetBook Color was released in 2012 as the first colored electronic ink device, which used E Ink's Triton display technology. E Ink in early 2015 also announced another color electronic ink technology called Prism. This new technology is a color changing film that can be used for e-readers, but Prism is also marketed as a film that can be integrated into architectural design such as "wall, ceiling panel, or entire room instantly." The disadvantage of these current color displays is that they are considerably more expensive than standard E Ink displays. The jetBook Color costs roughly nine times more than other popular e-readers such as the Amazon Kindle. As of January 2015, Prism had not been announced to be used in the plans for any e-reader devices.

Applications

An e-paper display on a watch refreshes to remove ghosts.

Several companies are simultaneously developing electronic paper and ink. While the technologies used by each company provide many of the same features, each has its own distinct technological advantages. All electronic paper technologies face the following general challenges:

• A method for encapsulation
• An ink or active material to fill the encapsulation
• Electronics to activate the ink

Electronic ink can be applied to flexible or rigid materials. For flexible displays, the base requires a thin, flexible material tough enough to withstand considerable wear, such as extremely thin plastic. The method of how the inks are encapsulated and then applied to the substrate is what distinguishes each company from others. These processes are complex and are carefully guarded industry secrets. Nevertheless, making electronic paper is less complex and costly than LCDs.

There are many approaches to electronic paper, with many companies developing technology in this area. Other technologies being applied to electronic paper include modifications of liquid-crystal displays, electrochromic displays, and the electronic equivalent of an Etch A Sketch at Kyushu University. Advantages of electronic paper include low power usage (power is only drawn when the display is updated), flexibility and better readability than most displays. Electronic ink can be printed on any surface, including walls, billboards, product labels and T-shirts. The ink's flexibility would also make it possible to develop rollable displays for electronic devices.

The Motorola F3 uses an e-paper display instead of an LCD.

Wristwatches

In December 2005, Seiko released the first electronic ink based watch called the Spectrum SVRD001 wristwatch, which has a flexible electrophoretic display and in March 2010 Seiko released a second generation of this famous electronic ink watch with an active matrix display. The Pebble smart watch (2013) uses a low-power memory LCD manufactured by Sharp for its e-paper display.

In 2019, Fossil launched a hybrid smartwatch called the Hybrid HR, integrating an always on electronic ink display with physical hands and dial to simulate the look of a traditional analog watch.

E-book readers

iLiad e-book reader equipped with an e-paper display visible in the sunlight

Main article: Comparison of e-readers

In 2004, Sony released the Librié in Japan, the first e-book reader with an electronic paper E Ink display. In September 2006, Sony released the PRS-500 Sony Reader e-book reader in the USA. On October 2, 2007, Sony announced the PRS-505, an updated version of the Reader. In November 2008, Sony released the PRS-700BC, which incorporated a backlight and a touchscreen.

In late 2007, Amazon began producing and marketing the Amazon Kindle, an e-book reader with an e-paper display. In February 2009, Amazon released the Kindle 2 and in May 2009 the larger Kindle DX was announced. In July 2010 the third-generation Kindle was announced, with notable design changes. The fourth generation of Kindle, called Touch, was announced in September 2011 that was the Kindle's first departure from keyboards and page turn buttons in favor of touchscreens. In September 2012, Amazon announced the fifth generation of the Kindle called the Paperwhite, which incorporates a LED frontlight and a higher contrast display.

In November 2009, Barnes and Noble launched the Barnes & Noble Nook, running an Android operating system. It differs from other e-readers in having a replaceable battery, and a separate touch-screen color LCD below the main electronic paper reading screen.

In 2017, Sony and reMarkable offered e-books tailored for writing with a smart stylus.

In 2020, Onyx released the first frontlit 13.3 inch electronic paper Android tablet, the Boox Max Lumi. At the end of the same year, Bigme released the first 10.3 inch color electronic paper Android tablet, the Bigme B1 Pro. This was also the first large electronic paper tablet to support 4g cellular data.

Newspapers

In February 2006, the Flemish daily De Tijd distributed an electronic version of the paper to select subscribers in a limited marketing study, using a pre-release version of the iRex iLiad. This was the first recorded application of electronic ink to newspaper publishing.

The French daily Les Échos announced the official launch of an electronic version of the paper on a subscription basis in September 2007. Two offers were available, combining a one-year subscription and a reading device. The offer included either a light (176g) reading device (adapted for Les Echos by Ganaxa) or the iRex iLiad. Two different processing platforms were used to deliver readable information of the daily, one based on the newly developed GPP electronic ink platform from Ganaxa, and the other one developed internally by Les Echos.

Displays embedded in smart cards

Flexible display cards enable financial payment cardholders to generate a one-time password to reduce online banking and transaction fraud. Electronic paper offers a flat and thin alternative to existing key fob tokens for data security. The world's first ISO compliant smart card with an embedded display was developed by Innovative Card Technologies and nCryptone in 2005. The cards were manufactured by Nagra ID.

Status displays

USB flash drive with E Ink-implemented capacity meter of available flash memory

Some devices, like USB flash drives, have used electronic paper to display status information, such as available storage space. Once the image on the electronic paper has been set, it requires no power to maintain, so the readout can be seen even when the flash drive is not plugged in.

Mobile phones

Motorola's low-cost mobile phone, the Motorola F3, uses an alphanumeric black-and-white electrophoretic display.

The Samsung Alias 2 mobile phone incorporates electronic ink from E Ink into the keypad, which allows the keypad to change character sets and orientation while in different display modes.

On December 12, 2012, Yota Devices announced the first "YotaPhone" prototype and was later released in December 2013, a unique double-display smartphone. It has a 4.3-inch, HD LCD on the front and an electronic ink display on the back.

On May and June 2020, Hisense released the hisense A5c and A5 pro cc, the first color electronic ink smartphones. With a single color display, with toggable front light running android 9 and Android 10.

Electronic shelf labels

Main article: Electronic shelf label

E-paper based electronic shelf labels (ESL) are used to digitally display the prices of goods at retail stores. Electronic-paper-based labels are updated via two-way infrared or radio technology and powered by a rechargeable coin cell. Some variants use ZBD (zenithal bistable display) which is more similar to LCD but does not need power to retain an image. 

Public transport timetables

Tram timetables on e-paper. Prague, prototype from May 2019.

E-paper displays at bus or trams stops can be remotely updated. Compared to LED or liquid-crystal displays (LCDs), they consume lower energy and the text or graphics stays visible during a power failure. Compared to LCDs, it is well visible also under full sunshine.

Digital signage

Main article: Digital signage

Because of its energy-saving properties, electronic paper has proved a technology suited to digital signage applications.

Computer monitor

Electronic paper is used on computer monitors like the 13.3 inch Dasung Paperlike 3 HD and 25.3 inch Paperlike 253.

Laptop

Some laptops like Lenovo ThinkBook Plus use e-paper as a secondary screen.

Electronic Tags

Typically, e-paper electronic Tags integrate e-ink technology with wireless interfaces like NFC or UHF. They are most commonly used as employees' ID cards or as production labels to track manufacturing changes and status. E-Paper Tags are also increasingly being used as shipping labels, especially in the case of reusable boxes. An interesting feature provided by some e-paper Tags manufacturers is batteryless design. This means that the power needed for a display's content update is provided wirelessly and the module itself doesn't contain any battery.

Other

Other proposed applications include clothes, digital photo frames, information boards, and keyboards. Keyboards with dynamically changeable keys are useful for less represented languages, non-standard keyboard layouts such as Dvorak, or for special non-alphabetical applications such as video editing or games. The reMarkable is a writer tablet for reading and taking notes.