Conductive Cellulose-Derived Carbon Nanofibrous Membranes with Superior Softness for High-Resolution Pressure Sensing and Electrophysiology Monitoring

Abstract

Here, a strategy to overcome the stiff and brittle nature of cellulose-derived carbon nanofibrils (CCNFs) is proposed through a facile, low-cost, and scalable approach. Flexible and conformal CCNFs with a low bending rigidity below 55.4 mN and tunable conductivities of 0.14–45.5 S m–1 are developed by introducing silanol as a multieffect additive in the electrospun hybrid nanofibrous network and subsequent carbonization at a relatively high temperature (900 °C) and chemical vapor deposition of polypyrrole (PPy) on the hybrid carbon nanofibril surface. Silica acts as a lubricant in each rigid carbon fiber to improve flexibility of the CCNF structure as well as a template during cellulose carbonization to prevent the melting of carbon nanofibrils. Meanwhile, the uniform coating of PPy leads to an improvement in electrical conductivity while conserving the porous structure and compressibility of the CCNF nets. These conductive hybrid CCNF films are evaluated as mechanoreceptors and physiological sensors, which are demonstrated to be applied in intelligent electronics including electronic skin, human–machine interfaces, and epidermic electrodes. The design or working principles of the hybrid CCNFs for achieving optimum applicable effects when applied in different scenarios are revealed.

Porous Conductive Textiles for Wearable Electronics

“…A variety of conductive textiles have been created by incorporating conductive materials into traditional textiles through methods like electroless deposition, dip coating, screen printing, and electrospinning. ,,− Electrophysiological signals, such as ECG, EMG, EEG, and EOG, can be collected by attaching the PCT-based electrodes to various sites on the human body (Figure ). ,− Skin-contact impedance is a key parameter for evaluating electrodes, as low contact impedance and low variations can contribute to stable and high-quality recordings of electrophysiological signals.…”

Electrospun Nanofiber-Based Bioinspired Artificial Skins for Healthcare Monitoring and Human-Machine Interaction

“…Comfortable, accurate, and real-time collection of physiological electrical signals is important for determining human health conditions. After prolonged conformal contact with human skin or joints, the ability to avoid elevated impedance caused by sweat and to withstand repeated mechanical deformation are crucial issues that need to be addressed [ 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 ]. Therefore, a flexible conductor with high permeability and stretchability (liquid-metal fiber mat, LMFM) was developed by Zheng et al in 2021 [ 171 ].…”