Preparation and evaluation of chitosan biocompatible electronic skin

Polydimethylsiloxane (PDMS) is often used in flexible electronic skin, due to their non toxic and tough. However, the lack of degradation and cell biocompatibility of PDMS would limit the potential use in the biological field. To overcome the limitation, PDMS was modified by surface treatment for enhancing cell adhesion and proliferation. This research is focused on preparation and evaluation of novel chitosan biocompatible electronic skin. Chitosan electronic skin was prepared by a thermal induced phase separation method, following treatment with NaOH gelating agent, followed by analyzing the surface morphology, swelling behavior, mechanical strength, degradation rate. The electrode was produced by screen printing technique, followed by analyzing the adhesion between the ink and cell biocompatibility. From scanning electron microscope (SEM) observations, NaOH gelated chitosan skin had the smooth surface morphology. The swelling ratio of all chitosan skin gelated by NaOH were less than 5%. The chitosan skin, prepared by 300k kDa chitosan gelated by NaOH for 3hr, had the smallest swelling ratio. Furthermore, its mechanical strength showed the highest value of Young's modulus (∼151 kPa). It indicated that 300 kD chitosan skin gelated by NaOH for 3hr had better size stability. All chitosan skins degraded about 20% of initial weight after 40 days in vitro shaking test. The adhesion strength of the silver inks on the surface of chitosan was better than carbon ink, and the electrical characteristic is almost the same with commercial polycarbonate (PC) substrate. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and SEM observation indicated that chitosan skin with silver electrode showed the cell biocompatibility. By further increasing the application of both screen imprinting technique and biopolymer, the idea of interdisciplinary can be achieved and it would be a creative revolution to the field of wearable device into tissue engineering.