Flexible wearable sensors to monitor human movement and
for electronic
skins must exhibit high sensitivity, a wide detection range, and waterproof
characteristics. This work reports a flexible, highly sensitive, and
waterproof sponge pressure sensor (SMCM). The sensor is made by assembling
SiO2 (S), MXene (M), and NH2-CNTs (C) on the
backbone of melamine sponge (M). The SMCM sensor exhibits excellent
sensitivity (10.8 kPa–1), an ultra-short response/recovery
time (40 ms/60 ms), a wide detection range (30 kPa), and an extremely
low detection limit (4.6 Pa). Benefiting from layer-by-layer self-assembly,
the sensor still exhibits excellent stability after 5000 cycles. In
addition, the SMCM sensor also has excellent waterproof performance
(a water contact angle of 142°), enabling it to operate unaffectedly
under wet conditions. The SMCM sensor can accurately detect small
body movements such as pulse and swallowing while also accurately
detecting finger and elbow movements. In addition, the sensor can
be designed as an array to construct an electronic skin for detecting
the magnitude and distribution of external pressure. This work holds
great application potential in next-generation electronic skin, fitness
detection, and flexible pressure sensors.