Smart mirrors

The presence of polymer, solvent, and ionic components in conducting polymers reminds one of the composition of the materials chosen by nature to produce muscles, neurons, and skin in living creatures. We will describe here some devices ready for commercial applications, such as artificial muscles, smart windows, or smart membranes other industrial products such as polymeric batteries or smart mirrors and processes and devices under development, such as biocompatible nervous system interfaces, smart membranes, and electron-ion transducers, all of them based on the electrochemical behavior of electrodes that are three dimensional at the molecular level. During the discussion we will emphasize the analogies between these electrochemical systems and analogous biological systems. Our aim is to introduce an electrochemistry for conducting polymers, and by extension, for any electrodic process where the structure of the electrode is taken into account. 

In a mirror-polished metal electrode substitute for the tungsten electrode we have a smart mirror. A similar photodetector-actuator automatically darkens a smart mirror in a car when a rear car uses high-beam lights. 

Any device (battery, supercapacitor, smart mirror, or muscle) stored in a compacted state requires an initial activation-relaxation before use. 

It s quite common when driving at night to be dazzled by the lights of the vehicle behind as they reflect from the driver s new-view or door mirror. We can prevent the dazzle by forming a layer of coloured material over the reflecting surface within an electrochromic mirror. Such mirrors are sometimes called smart mirrors or electronic anti-dazzle mirrors . 

In general, the term electrochromism is used to describe the change in light absorption as a result of an electrochemical reaction. Recent interest in electrochromism stems from its potential applications in numerous devices, such as flat screen displays, antidazzle mirrors, smart windows, and others. 

FIGURE 33.1 Schematic illustration of (a) a smart window or transmission display (b) a front-illumination display (c) an antidazzle mirror. (From Bohnke, 1992, with permission of Cambridge University Press.)... 

Electrochromic materials are electroactive compounds whose visible spectra depend on the oxidation state. Possible applications are smart windows, displays, mirrors, and so on. Among the most important performance aspects in electrochromic materials, the reversibility and lifetime of the material to repeated cycles, the time of response (usually in order of seconds), the colors of the oxidized/reduced forms and the change in absorbance upon redox switching (contrast) are of interest. 

The chemistry and applications of the colour change grouping, containing all the well-known isms of chromic phenomena, namely photochromism, thermo-chromism, ionochromism, electrochromism and solvatochromism, as well as the lesser-known ones such as tribochromism and vapochromism, are covered in Chapter 1. These chromic phenomena impinge on our everyday life, e.g. in photo-chromic spectacle lens, thermochromic temperature indicators, fax paper, smart windows and mirrors and in visual displays. 

The materials that change colour on passing a charge are called electrochromes, and these can be classified into three groups. In the first type the colouring species remain in solution in the second type the reactants are in solution but the coloured product is a solid the third type are those where all the materials are solids, e.g. in films. The first type is used in car, anti-dazzle, rear-view mirrors, the second type in larger mirrors for commercial vehicles and the third type in smart windows (see section 1.5.4.2). 

The mirror is smart enough to understand the questions. Ordinarily the interfaces of modeling and innovation are not so well defined. How much time would you spend in front of that mirror What questions would you ask the mirror What questions would you always ask the mirror What questions would you never ask the mirror Which images would you archive and preserve Which images would you make sure once you saw them you never generated again ... 

Due to its electrochromic properties, i.e., a reversible color change upon application of suitable electric potential, tungsten trioxide has been employed and widely used in electronic displays, smart windows, simroofs, and rear and side view mirrors [60-63]. More recently, due to its chemical stability in acidic aqueous media and interesting photoelectrochemical properties, it has been proposed as a promising candidate in water photoelectrolysis processes [64—68]. 

Electrochromic materials is a remarkable and productive research area over the last three decades since it has potential applications in smart window products, e-papers, optical shutters, transmissive and reflective displays, self-darkening mirror devices, and optical memories. The electrochromic effect has been observed in metal oxides (e.g., WO3),... 

The system architecture of the RFID-enabled SDS system is shown in Fig. 10.2. The system consists of RFID-embedded dressing mirrors, smart fitting rooms, a... 

Continued, (c) Smart dressing mirror displaying mix-and-match items based on the customer s selected item, (d) A customer inside the smart fitting room interacting with the system for more product details. 

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