3D printing lignin carbonized nanotube and cellulose nano fiber aerogel for wearable pressure sensors

Abstract

The nanocellulose represents an important sustainability and chemical stability candidate for conductive 3D aerogel sensors, while introducing additional conductive additives is necessary. Herein, the as developed lignin derived carbonized nanotube (LCNT) in our lab was adopted as conductive ingredient to fabricate cellulose nanofiber (CNF) based composite aerogel by 3D printing. Specifically, the as-prepared LCNT/CNF composite aerogel with ratio of 85:15 in weight presented homogeneous porous morphology with well dispersed and penetrated LCNT in CNF porous matrix, providing a piezoresistive type pressure sensor. Stable signals were achieved under testing range from 0.2 to 9.8 kPa, with response time between 100 and 200 ms, related to the testing accuracy. The mechanical property of the as-prepared composite aerogel was found to be satisfactory. Under a constant 30 % compression strain for 1000 cycles, 92.5 % stress retention was maintained, and the ultimate stress was tested to be 16.64 kPa. This work provided a customized wearable pressure sensor with satisfactory comprehensive performance made completely from cellulose and lignin renewable natural polymers.