A porous carbon nanotube/polydimethylsiloxane strain sensor with low strain monitoring limit prepared by sustainable emulsion method

As the core component of wearable electronics, flexible strain sensors have played an undeniable role in production and life, receiving widespread attention. However, the challenge persists in finding a simple and environmentally friendly preparation method for high -performance flexible strain sensors. Here, we present a porous strain sensor (KCNT/PDMS-P) prepared through an emulsion method that combines modified carbon nanotubes (KCNTs), polydimethylsiloxane (PDMS), and water. The carbon nanotubes (CNTs) undergo modification using KH550 in a water/ethanol solution to enhance their interface interaction with PDMS and improve KCNT dispersion in PDMS. The improved dispersion and porous structure give the KCNT/PDMS-P strain sensor a lower percolation threshold (0.49 wt%). Additionally, the KCNT/PDMS-P with 1.5 wt% KCNTs exhibits excellent sensing performance, featuring a gauge factor (GF) of 129, a minimum strain monitoring limit of 0.1%, and the ability to monitor various strains and frequencies. In the final exploration of the sensor ' s practical application, we achieve effective detection of human joint motion and facial expressions.