Ionogel infiltrated paper as flexible electrode for wearable all-paper based sensors in active and passive modes

Recently, the study of flexible electrode sets the foundation for building flexible and wearable electronics. However, the most majority of existing flexible electrodes have problems such as high cost (noble metal deposition), complex fabrication (lithography), and environmentally unfriendly (non-degradable polymers). Here, we present an ionogel infiltrated paper based flexible electrode (IIPFE) with advantages of low cost, disposable, and facile manufacturing process, and two kinds of flexible all-paper based force sensors based on these electrodes have been fabricated. The ionogel infiltrated paper has a good conductivity of 1.78 × 10−1 S m−1 and could be processed into arbitrary shape by infiltration of blocking agent. The IIPFE based passive-mode piezoresistive sensor has sensitive detecting ability to dynamic and static pressure in a passive mode, and the IIPFE based self-powered active-mode sensor with a structure of triboelectric nanogenerator (TENG) has a higher sensitivity and a good linearity (20.6 mV N−1) in measuring impulsive force. This work provides a potential flexible electrode for the future flexible, wearable, disposable, and portable electronic devices.