Application of intrinsically conducting polymers in flexible electronics

Abstract

Intrinsically conducting polymers (ICPs), such as polyacetylene, polyaniline, polypyrrole, polythiophene, and poly(3,4‐ethylenedioxythiophene) (PEDOT), can have important application in flexible electronics owing to their unique merits including high conductivity, high mechanical flexibility, low cost, and good biocompatibility. The requirements for their application in flexible electronics include high conductivity and appropriate mechanical properties. The conductivity of some ICPs can be enhanced through a postpolymerization treatment, the so‐called “secondary doping.” A conducting polymer film with high conductivity can be used as flexible electrode and even as flexible transparent electrode of optoelectronic devices. The application of ICPs as stretchable electrode requires high mechanical stretchability. The mechanical stretchability of ICPs can be improved through blending with a soft polymer or plasticization. Because of their good biocompatibility, ICPs can be modified as dry electrode for biopotential monitoring and neural interface. In addition, ICPs can be used as the active material of strain sensors for healthcare monitoring, and they can be adopted to monitor food processing, such as the fermentation, steaming, storage, and refreshing of starch‐based food because of the resistance variation caused by the food volume change. All these applications of ICPs are covered in this review article.

Flexible Sensors Based on Conductive Polymers

“…Polymers like polyurethane (PU) or poly(dimethylsiloxane) are used due to their excellent optical and mechanical properties such as elasticity, low density, or transparency. The second strategy is the use of conductive polymers as the sensor [48] but also as a filler [49]. Significant advances have been made in improving the flexibility of conjugated polymers by changing their chemistry or the strategies to design the material [50].…”

Strategies for interface issues and challenges of neural electrodes

“…Alternately, PEDOT is more favored than PPy due to the following factors: (i) PEDOT has a narrow band gap, 217 which promotes the shift of charges in the polymer chain; (ii) PEDOT has higher conductivity, which facilitates the preparation of neural electrodes with better electrical activity; 55,67,218 (iii) it has higher electrochemical stability, which is essential for obtaining a stable signal; 219–221 and (iv) PEDOT reveals better biocompatibility than PPy, which is an indispensable requirement for practical applications. 222–225 By adopting PEDOT:PSS as a conductive material, Blau et al 226 prepared an extendable and non-cytotoxic all-polymer electrode array. This electrode showed good stability in capturing muscle's action potential in vivo .…”

Conversion of Plastic Waste into Supports for Nanostructured Heterogeneous Catalysts: Application in Environmental Remediation

“…This follows from the principle that for there to be a flow of electric current, there must be electron transfer; since plastics have a low density of free electrons, they are good insulators [62]. Exceptions are the so-called intrinsically conducting polymers, which are mostly studied in the field of organic electronics, sensors, energy storage and soft robotics [63].…”