A Dual-Mode Wearable Sensor Based on Bacterial Cellulose Reinforced Hydrogels for Highly Sensitive Strain/Pressure Sensing

Flexible and wearable sensors are fast establishing their status as go-to devices for human motion detection. A bacterial cellulose-reinforced hydrogel is fabricated through a facile and scalable freezing-thawing process with Ca2+ crosslinking for strain and pressure sensing. Polyvinyl alcohol/sodium alginate/bacterial cellulose/modified carbon nanotube and carbon black hydrogels assembled as piezoresistive strain sensors and capacitive pressure sensors exhibit an excellent synchronicity between mechanical load and electrical signal, good stability under various strains and pressures, an ability to distinguish strains and pressures, and extraordinary cycling repeatability and durability during loading/unloading process. Moreover, the dual-mode sensor can be used for monitoring human motion, such as limb movement, walking, and grasping weights, suggesting its great potential in flexible and wearable devices.