Soft piezoresistive pressure sensors play an underpinning
role
in enabling a plethora of future Internet of Things (IoT) applications
such as human–robot interaction (HRI) technologies, wearable
devices, and metaverse ecosystems. Despite significant attempts to
enhance the performance of these sensors, existing sensors still fall
short of achieving high strain tolerance and linearity simultaneously.
Herein, we present a low-cost, facile, and scalable approach to fabricating
a highly strain-tolerant and linearly sensitive soft piezoresistive
pressure sensor. Our design utilizes thin nanocracked gold films (NC-GFs)
deposited on poly(dimethylsiloxane) (PDMS) as electrodes of the sensor.
The large mismatch stress between gold (Au) and PDMS induces the formation
of secondary wrinkles along the pyramidal-structured electrode under
pressure; these wrinkles function as protuberances on the electrode
and enable exceptional linear sensitivity of 4.2 kPa–1 over a wide pressure range. Additionally, our pressure sensor can
maintain its performance even after severe mechanical deformations,
including repeated stretching up to 30% strain, due to the outstanding
strain tolerance of NC-GF. Our sensor’s impressive sensing
performance and mechanical robustness make it suitable for diverse
IoT applications, as demonstrated by its use in wearable pulse monitoring
devices and human–robot interaction systems.