*Xudong Tao, Hazel E. Assender, University of Oxford, Oxford, United Kingdom
High-throughput/cheap roll-to-roll processing is of interest to scale up the manufacture of flexible electronics. One example device we are investigating is thermoelectric generators to provide a small constant source of power for wearable devices. However, there are still many issues to be addressed. For example, for high-throughput roll-to-roll manufacture of material with the slow deposition rate required for many high-quality functional materials (typically by sputtering), dictates that only a thin layer is deposited, and we have investigated the impact of using very thin functional layers. Here we have successfully demonstrated manufacture of thermoelectric layer sputtered onto a polymer substrate at room temperature on a fast moving substrate in our vacuum webcoating roll-to-roll facility, and surprisingly found that a thinner coating could possess better thermoelectric behaviours due to an energy barrier mechanism and a possible quantum confinement effect. This gives a significant boost to the commercialization of flexible thermoelectric generators. We will report on our exploration of other challenges for roll-to-roll production of TEGs: improving the mechanical resilience of the devices under tensile and bending stresses, and manufacture of devices with in-line patterning of the layers.