Stretchable Strain Sensors Based on Two- and Three-Dimensional Carbonized Cotton Fabrics for the Detection of Full Range of Human Motions

Recently, flexible strain/pressure sensors have made rapid development under the stimulus of the demand for wearable electronics. Those based on carbonized fabrics have attracted great attention by virtue of their outstanding sensing performance, facile fabrication, and low cost. However, it is still challenging for a stretchable sensor to achieve both a wide sensing range and high sensitivity up to now. Therefore, stretchable strain sensors based on carbonized cotton fabrics (CFs) with two- and three-dimensional (2D and 3D) structures are designed utilizing a simple one-step carbonization process, realizing the complementary performance requirement for sensitivity and working range. The 2D sensor based on a planar structure shows a high gauge factor (GF) of 24.12 within a stretching range of 50–100%, while the 3D sensor based on a helical structure exhibits a linear response within a broad strain range of 0–180%. Furthermore, both sensors have been demonstrated to have excellent stability, low detection limit, and good reliability and are also successfully applied to detect small physical stimuli and large joint motions. It is believed that our sensors have great potential in wearable devices for the detection of the full range of human activities.