Interlinked Microcone Resistive Sensors Based on Self-Assembly Carbon Nanotubes Film for Monitoring of Signals

Abstract

Flexible pressure sensors still face difficulties achieving a constantly adaptable micronanostructure of substrate materials. Interlinked microcone resistive sensors were fabricated by polydimethylsiloxane (PDMS) nanocone array. PDMS nanocone array was achieved by the second transferring tapered polymethyl methacrylate (PMMA) structure. In addition, self-assembly 2D carbon nanotubes (CNTs) networks as a conducting layer were prepared by a low-cost, dependable, and ultrafast Langmuir–Blodgett (LB) process. In addition, the self-assembled two-dimensional carbon nanotubes (CNTs) network as a conductive layer can change the internal resistance due to pressure. The results showed that the interlinked sensor with a nanocone structure can detect the external pressure by the change of resistivity and had a sensitive resistance change in the low pressure (<200 Pa), good stability through 2800 cycles, and a detection limit of 10 kPa. Based on these properties, the electric signals were tested, including swallowing throat, finger bending, finger pressing, and paper folding. The simulation model of the sensors with different structural parameters under external pressure was established. With the advantages of high sensitivity, stability, and wide detection range, this sensor shows great potential for monitoring human motion and can be used in wearable devices.

Design of Double Conductive Layer and Grid-Assistant Face-to-Face Structure for Wide Linear Range, High Sensitivity Flexible Pressure Sensors

“…Flexible pressure sensors can transduce mechanical stimuli into electrical signals. In recent years, they have drawn a tremendous amount of attention because of their potential applications in artificial electronic skins, − human-machine interaction, − health monitoring, − etc. Recently, piezoresistive sensors have been widely reported, owing to their facile device design, modest demand on signal collection circuits, and outstanding reliability. − High sensitivity and broad linear range are vital for a desired flexible piezoresistive sensor to adapt to diverse applications.…”

Synergistic control of engineered nanostructures toward sensitivity and reliability of a flexible piezoresistive pressure sensor

“…In particular, piezoresistive sensors with an interdigitated nanostructured medium, that is, face-to-face assemblies of nanostructured substrates, can induce much greater changes in the contact area and localized stress concentration than those using a single nanostructured medium, resulting from the formation of extra current paths through the unsimultaneous contact of regular nanopatterns. [27][28][29][30] The geometrical morphologies of the nanopatterned media have a close relationship with the contact behavior under local pressure for the sensing performance associated with piezoresistive performance. For example, a pressure sensor with a very small nano/microstructure has high sensitivity in a low-pressure range; however, the reliability of its signal detection is lowered.…”