Flexible Ti3C2Tx MXene/ink human wearable strain sensors with high sensitivity and a wide sensing range

Abstract

Flexible strain sensors still face great challenges in combining high sensitivity, wide detection range, good mechanical stability and simple manufacturing processes into sensors. Herein, this paper reports a simple and low cost strain sensor fabricating method based on two-dimensional (2D) material (MXene) and ink, which can be large-scale fabricated into multiduty sensors with high sensitivity and excellent durability by spray-coated process and wrapped by nylon fabric. Owing to the fact that MXene has excellent dispersion in printing ink material, the sensor obtains low percolation threshold of 3.6 wt% and a percolation network based on Ti3C2Tx MXene/ink composites was precisely designed. The migration of the MXene lamination leads to a large change in resistance, while the ink coating restricts the large displacement of the nanometer lamella to maintain the connectivity of the conductive path in the large strain region. The strain sensing test shows that the MXene/ink encapsulated by nylon fabric strain sensor exhibits a high sensitivity (gauge factor of 27.2 and 170.9 under 0 %–25 % and 25 %–29.7 % strain, respectively), good linearity (R-Square >0.967), and excellent reliability and stability (>2950 cycles). The as-developed MXene/ink strain sensor was demonstrated to monitor real-time both tiny and large human activities, showing that it has great potential in the field of wearable strain sensor.