Parallel\nMicrocracks-based Ultrasensitive and Highly Stretchable Strain Sensors

Abstract

There is an increasing demand for\nflexible, skin-attachable, and wearable strain sensors due to their\nvarious potential applications. However, achieving strain sensors\nwith both high sensitivity and high stretchability is still a grand\nchallenge. Here, we propose highly sensitive and stretchable strain\nsensors based on the reversible microcrack formation in composite\nthin films. Controllable parallel microcracks are generated in graphite\nthin films coated on elastomer films. Sensors made of graphite thin\nfilms with short microcracks possess high gauge factors (maximum value\nof 522.6) and stretchability (ε ≥ 50%), whereas sensors\nwith long microcracks show ultrahigh sensitivity (maximum value of\n11 344) with limited stretchability (ε ≤ 50%).\nWe demonstrate the high performance strain sensing of our sensors\nin both small and large strain sensing applications such as human\nphysiological activity recognition, human body large motion capturing,\nvibration detection, pressure sensing, and soft robotics.