Silver nanowire-based transparent conducting electrodes (TCE) find applicability in a wide variety of devices such as flexible heaters, wearable devices, smart windows, flexible displays, touch screens, solar cells and sensors. Flexible heaters have attracted great attention because of their applicability in areas such as defrosters/defoggers in automobile windows, helmet visors, goggles, camera lens heater, thermochromic displays, and in wearable electronics such as electric blankets, smart garments, medical thermotherapy pads in physiotherapies, and for treating arthritis. Silver nanowire (Ag NW) based TCEs are promising candidates for heater applications because of their high electrical conductivity, optical transmittance, and mechanical flexibility.

In this work, a flexible, low resistance heater based on silver nanowires and neutral poly (3,4- ethylenedioxythiophene) poly(styrene sulphonate) (PEDOT:PSS) is fabricated by direct writing. Pure silver nanowires have poor adhesion to substrate, poor environmental stability and high surface roughness. These disadvantages can be overcome by blending with PEDOT: PSS to form a nanocomposite ink. The nanocomposite ink was printed on flexible polyethylene terepthalate (PET) substrate and laminated with polydimethylsiloxane (PDMS) for environmental protection. Transparency and conductivity were tuned to achieve optimum optoelectronic property. The working of the heater was demonstrated by using evaporation of water as a model system. Heater shows uniform temperature distribution and can be operated at low operating voltage. The required temperature of the heater was achieved at low response time. For wearable heaters, the temperature should be less than 45 ͦC which can be achieved at low operating voltage. The heater shows good repeatability and cyclic thermal stability. The temperature distribution modelling using MATLAB and COMSOL was also carried out and compared with the experimental data. A prototype wearable device with temperature cut-off and feedback is being developed.