Printed Preparation of Cellulose-Based Hydrogel Sensors for Human Motion Detection

This study aims to prepare gel ink from cellulose, polyvinyl alcohol, and carbon nanotubes, and to prepare hydrogel sensors by direct writing printing and freezing cycle and test their performance. Firstly, TEMPO-oxidized cellulose was prepared by the TEMPO oxidation method, and then PVA and CNT were added to prepare gel ink, The gel sensing film was printed by direct writing, and then the hydrogel sensor that could be used for human motion detection was obtained through the freezing cycle. The degree of stretching of the hydrogel sensor can reach 500%. At 100% stretching, the response time is 180ms and the sensitivity is 1.12. The movement of human elbows, wrists, and knuckles can be very accurately identified. TEMPO oxidizes cellulose and carbon nanotubes to improve cellulose hydrogels’ conductivity and mechanical properties, and direct printing can easily and efficiently print the structure of the prepared sensor. The prepared hydrogel sensor shows high flexibility, high conductivity, and high sensitivity, which can monitor the large and small movements of the human body for a long time and stably, which is of great significance for the preparation and application of subsequent cellulose hydrogel sensors.