A biodegradable wearable flexible sensor based on natural wheat flour polymer for human motion and sweat monitoring

Fabrication of economical and eco-friendly flexible sensors is highly demanded in developing wearable biomedical devices. In this study, an eco-friendly strain and sweat sensor has been successfully assembled based on innovative composites consisting of carbon black (CB) and natural flour polymer, which are entirely green and biodegradable. A film-based sensing device has been developed to measure electrical resistance and strain simultaneously and continuously, owing to the highly sensitive resistance responsibility of the as-developed hybrid of CB and wheat flour (CB-dough). Furthermore, the influence of simulated sweat on the electric response of such sensor was also investigated. Repeatable relationships in resistance versus strain were revealed and obtained for varying samples with different content of simulated sweat, in which the amplitude of resistance was directly proportional to the concentration of NaCl. Accordingly, the as-developed CB-dough sensor was efficaciously used for durable surveillance of human activity and real-time feedback of sweat secretion during body motion. This work offers a simple and cost-effective way to manufacture flexible strain sensors, with a broad application prospect in wearable electronics, artificial intelligence systems, and other bio-sensors.