posted on 2023-03-17, 14:04authored byMengqin Zhang, Mingxin Gu, Li Shao, Guanyin Cheng, Hailin Gao, Bihao Sun, Sen Li, Tian Tang, Nan Li, Yuanbang Yi, Dacheng Wei, Ce Yang, Dapeng Wei
Flexible positive pressure sensors have been studied
extensively
and have been used in a lot of scenarios. However, negative pressure
detection is also in demand in some scenarios, such as fluid mechanics
analysis, air pressure sensing, and so on. Flexible wearable sensors
that can detect both positive and negative pressures will greatly
broaden the application field. In this paper, we report a flexible
highly sensitive ionic gel (IG) pressure sensor, which is simple and
of low cost to prepare and can reliably detect a large pressure range
from −98 to 100 kPa under an atmospheric pressure of about
982 hPa. The IG dielectric layer is composed of polyvinyl alcohol
and phosphoric acid with a random microstructure of sandpaper inversion.
The sensor exhibits flexibility, cycling stability, and high sensitivity
under both negative and positive pressures (S = 84.45
nF/kPa for the negative pressure section, S = 25.61
nF/kPa for the positive pressure section). These sensors could be
worn on the body not only to test breathing and pulse but also to
measure air pressure for estimating the altitude, showing that the
flexible full-pressure sensors have a wider application range in wearable
electronics.