  As a new class of two-dimensional transition-metal carbide and carbonitride,
MXene have been widely used in the energy storage, sensor, catalysis,
electromagnetic interference shielding and other field. It is a challenge to
simultaneously realize a sensor of extremely high sensitivity, wide detection
limits, low power consumption and good mechanical stability. In this work,
taking advantage of high conductivity of MXene and porous structure of
polyvinyl butyral, a highly sensitive piezoresistive sensor was fabricated. The
fabricated MXene/PVB-based sensor exhibits highly sensitive reliably with a
factor of ~11.9 kPa^-1, ~1.15 kPa^-1 and ~0.20 kPa^-1 in the ranges of 31.2
Pa-312 Pa, 312 Pa- 62.4 kPa and 62.4 kPa-1248.4 kPa, respectively. The sensor
has a wide detection range (~31.2 Pa to ~2.205 MPa), low detection limit (6.8
Pa), low detection voltage (0.1 mV), low power consumption (~3.6 * 10^-10 W),
fast response time ( ~110 ms), as well as good mechanical stability (over
10,000 maximum-pressure cycles). Moreover, it is demonstrated that the sensor
can detect subtle bending and release activities of human, including arterial
pulses and voice signal, which is potentially suitable as a wide detection
range, highly sensitive and low power consumption piezoresistive sensor. This
work provides a new avenue to expand the application of MXene-based flexible
pressure sensor in the field of wide sensing range and ultra-low power
consumption.
