posted on 2019-06-26, 00:00authored byLibo Gao, Yuejiao Wang, Xinkang Hu, Wenzhao Zhou, Ke Cao, Yongkun Wang, Weidong Wang, Yang Lu
A highly sensitive
portable piezoresistive sensor with a fast response
time in an extended linear working range is urgently needed to meet
the rapid development of artificial intelligence, interactive human–machine
interfaces, and ubiquitous flexible electronics. However, it is a
challenge to rationally couple these figures of merit (sensitivity,
response time, and working range) together as they typically show
functionally correlative behavior in the sensor. Here, we aim at introducing
the hierarchical pores across several size orders from micro- to larger
scale into the intrinsically flexible graphene-based electrode materials
that overcome this limitation of the sensor. We achieved a flexible
sensor with a prominent sensitivity of 11.9 kPa–1 in the linear range of 3 Pa to ∼21 kPa and a rapid response
time of 20 ms to positively monitor the pulse rate, voice recognition,
and true force value for biomedical and interactive human–machine
interface application assisted by an analog-digital converter. More
interesting is the carbon-nanotube-doped graphene that also served
as the electrode in the waterproof supercapacitor to actively drive
the sensor as a whole flexible system. We believe our findings not
only offer a general strategy for the graphene-based platform in flexible
electronics but also possess other intriguing potential in functional
application such as the heat dissipation component in electron devices
or seawater filtration in environment application.