PEDOT: PSS Thermoelectric Generators Printed on Paper Substrates

Abstract

Flexible electronics is a field gathering a growing interest among researchers and companies with widely varying applications, such as organic light emitting diodes, transistors as well as many different sensors. If the circuit should be portable or off-grid, the power sources available are batteries, supercapacitors or some type of power generator. Thermoelectric generators produce electrical energy by the diffusion of charge carriers in response to heat flux caused by a temperature gradient between junctions of dissimilar materials. As wearables, flexible electronics and intelligent packaging applications increase, there is a need for low-cost, recyclable and printable power sources. For such applications, printed thermoelectric generators (TEGs) are an interesting power source, which can also be combined with printable energy storage, such as supercapacitors. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), or PEDOT:PSS, is a conductive polymer that has gathered interest as a thermoelectric material. Plastic substrates are commonly used for printed electronics, but an interesting and emerging alternative is to use paper. In this article, a printed thermoelectric generator consisting of PEDOT:PSS and silver inks was printed on two common types of paper substrates, which could be used to power electronic circuits on paper.

Printed Thermoelectrics

“…Carbon-based thermoelectric materials have been shown to be processable onto flexible substrates such as polyimides, polyethylene terephthalates (PETs), and paper. [118,119] When examining the materials properties for use in wearable textile TEG devices for example, it is essential that the design considerations account for mechanical durability and allow tuning for desired viscoelastic traits. [120] This is because the devices will be under mechanical stress when bent or stretched.…”

Highly Filled Papers, on their Manufacturing, Processing, and Applications

“…The thermal conductivity of cellulose papers with a copper filler content of up 14.3 wt% (or a ratio of 1:6 between copper particles and pulp fibers) could already be dramatically increased . In previous studies, electronic circuits and piezoelectric structures had been printed onto cellulose papers . Similarly, circuit structures made from Ti 2 SiC 3 could be successfully ink‐jet printed onto preceramic alumina papers by Carrijo et al The circuitry patterns on highly filled papers might be integrated into low voltage energy sources, memory cells or a variety of sensors.…”

“…While the Ti 2 SiC 3 ink, which has been developed by Carrijo et al, contained submicron‐sized particles, Milardović et al presented an ink for cellulose papers with spherical silver nanoparticles of an average diameter of 2.5 nm, which is the finest particle size for particles in silver metal inks to this date. By printing patterns of precious metal nanoparticles on cellulose papers several different microelectronic structures could be generated: RFID sensors and sensors with a memory effect to measure humidity, thermoelectric generators and gas sensors oxygen sensors for hydrogen sulfide or oxygen . The printed thermoelectric low voltage energy sources and sensors tested on cellulose papers can be installed onto a wide range of food packaging materials, including card board boxes.…”

Electronic performance of printed PEDOT:PSS lines correlated to the physical and chemical properties of coated inkjet papers

“…Temperature sensor and thermoelectric generator applications. We would like to refer the reader to two other studies 26,63 that were performed in parallel to the present research where some of the substrates studied here were used to print a thermosensor 63 and a triboelectric generator applications. 26…”