Cellulose Nanofibers/PEDOT:PSS Conductive Aerogel for Pressure Sensing Prepared by a Facile Freeze-Drying Method

The application of flexible wearable pressure sensorsin the fieldsof pressure sensing, electronic skin, and human health monitoringhas attracted a lot of attention. Herein, cellulose-nanofiber (CNF)-basedaerogels with conducting polymer poly-(3,4-ethylene dioxythiophene)/poly-(styrenesulfonate)(PEDOT:PSS) and glutaraldehyde (GA) as cross-linking agent were designedand prepared by sol-gel cross-linking and freeze-drying. Withoutany special treatment, these aerogels presented good flexibility andpiezoresistive properties. As the analysis of SEM, Raman spectrum,and XPS, the introduction of GA not only improves the mechanical propertiesof aerogel (the compressive strength at 80% strain has increased from48 to 66 kPa) but also affects the doping state of PEDOT, which improvesthe sensitivity of aerogel (from 10.65 to 15.18 kPa(-1)). In addition, the sensor has been successfully applied to monitorhuman movements, including not only large movements (joint movements)but also small-scale muscle movements (cheek puffing and articulationrecognition). It shows its potential as a widely used green pressuresensor.