Silicone/ broadleaf wood fiber /MWCNTS composite stretchable strain sensor for smart object identification

Abstract

Stretchable strain sensors have been rapidly developing in recent years. Fabricating strain sensors with both large workable strain range and high sensitivity via a low-cost and straightforward process is still challenging. Here, this work created a multi-walled carbon nanotubes (MWCNTs) / broadleaf wood fiber (BWF) film, the highly micro-porous network of which allows a slow infiltration of liquid silicone in a vacuum environment to form an elastic composite, serving as a stretchable strain sensor. The sensor showed an ultra-wide strain of up to 440% and high sensitivity of GF (gage factor) of 3.3 at 0∼200% strain and of 7.8 at 200∼440% strain. In addition, the sensor is able to endure 5500 cyclic loading/unload at 100% strain with no damage in its mechanical structure and small variation in electrical resistance. To demonstrate its practicality, the sensor was incorporated into a soft pneumatic griper and utilized as a bending sensor to detect the griper deformation. The system demonstrated a high accuracy of 99.33% in the classification of lab beakers using a data-driven framework built with a trained Support Vector Machine (SVM) algorithm.