posted on 2022-05-11, 21:44authored byJin Ji, Chengpeng Zhang, Shaohua Yang, Yongzhi Liu, Jilai Wang, Zhenyu Shi
Flexible
strain sensors occupying a large part of human body detection
and wearable electronics, which have a wide sensing range and high
sensitivity, are crucial in fully monitoring human motion signals.
This study proposed a strategy to construct flexible strain sensors
based on the V-groove/wrinkles hierarchical array. The V-groove array
was prepared on a polydimethylsiloxane (PDMS) substrate through mold
transfer printing. The gold film was sputtered on the prestretching
PDMS substrate, and the V-groove/wrinkles hierarchical array was formed
after strain release. Compared with the sensors based on single-scale
wrinkle structures and a V-groove array, the fabricated strain sensor
with the hierarchical array showed high sensitivity (maximum gauge
factor up to 2,557.71) and a wide sensing range (up to 45%). In addition,
the dynamic characteristics of the sensor were investigated in detail,
indicating that the sensor had a fast response (less than 130 ms),
a low detection limit (0.1% strain), and good stability (almost no
performance loss after 10,000 cycles). In practical applications,
the sensor was used to detect sizable physical motion and weak physiological
signals, demonstrating great potential application value in human
motion detection. This study could provide new ideas for preparing
high-performance flexible strain sensors.