Biodegradable Flexible Substrate Based on Chitosan/PVP Blend Polymer for Disposable Electronics Device Applications.

To provide a more sustainable future, development and implementation of green electronics incorporating natural materials has become an essential requirement. In this study, we demonstrated a low-temperature and low-cost fabrication route to develop chitosan/PVP (CHP) substrate for flexible electronics device applications. A combination of natural polymer (chitosan) and synthetic polymer (poly(vinylpyrrolidone), PVP) has been used to fabricate biodegradable, low-cost, and flexible substrate. The CHP substrate has been prepared by the solution casting method. The CHP flexible substrate demonstrates a high optical transmittance (∼90% in the visible region), high-temperature stability (up to 250 °C), smooth surface, and good mechanical stability along with a high biodegradation rate (within 6 days) into the soil. Radio frequency (RF) sputtering and thermal evaporation techniques have been used to deposit high-quality ZnO thin films and Au/Ti electrodes over the CHP substrate. This fabricated metal-semiconductor-metal (MSM) device gives a clear indication about the accountability of the CHP polymer substrate as a potential option for flexible electronics. The current-voltage characteristic with flat and bending cycles (three flat-bending-flat cycles) shows almost same current conduction. These flexible CHP substrates can find a new way toward environmentally friendly, flexible electronics.