Bacterial cellulose carbon aerogel with ultra-high stress retention for flexible sensor

In recent years, interest in biomass-derived conductive carbon aerogels for flexible wearable sensor devices has been increasing. This paper presents a novel, streamlined methodology for synthesizing nitrogen-phosphorus co-doped carbon aerogels from bacterial cellulose (BC) that exhibit exceptional mechanical and sensing properties. The strategic incorporation of ammonium and phosphate reduces defects during the carbonization phase. Substituting traditional solvents in the BC hydrogel with tert-butanol (TBA) preserves the integrity of the continuous three-dimensional aerogel network throughout lyophilization. Following pyrolysis under optimized carbonization conditions, the aerogels display regular, parallel microtubular structures that enhance their compression fatigue resistance. The resultant nitrogen-phosphorus co-doped BC carbon aerogel demonstrates an extraordinarily high stress retention rate (98.4 % after 1000 compression cycles) and maintains 100 % retention in cyclic compression tests, surpassing all similar compressible materials documented in the past five years. When employed in wearable piezoresistive pressure sensors, the carbon aerogel exhibits heightened sensitivity (0.57 kPa^-1) and an extensive operational range (0.239-6.714 kPa), enabling the detection of diverse human movements.