Linearly Sensitive Pressure Sensor Based on a Porous Multistacked Composite Structure with Controlled Mechanical and Electrical Properties

Abstract

Capacitive pressure sensors based on porous structures have been extensively explored for various applications because their sensing performance is superior to that of conventional polymer sensors. However, it is challenging to develop sufficiently sensitive pressure sensors with linearity over a wide pressure range owing to the trade-off between linearity and sensitivity. This study demonstrates a novel strategy for the fabrication of a pressure sensor consisting of stacked carbon nanotubes (CNTs) and polydimethylsiloxane. With the addition of carbon nanotubes, the structure is linearly compressed due to the reinforced mechanical properties, thereby resulting in high linearity. Additionally, the percolation effect is boosted by the CNTs having a high dielectric constant, thus improving the sensitivity. The pressure sensor exhibits linear sensitivity (R 2 = 0.991) in the medium-pressure range (10−100 kPa). Furthermore, it delivers excellent performance with a fast response time (∼60 ms), in conjunction with high repeatability, reproducibility, and reliability (5 and 50 kPa/1000 cycles). The fabricated sensors are applied in wearable devices to monitor finger bending and detect finger motions in real time with high precision. The large-area sensor is integrated with a neural network to accurately recognize the sitting posture on a plane, thereby demonstrating the wide-range detection performance.

Interface Engineering in Chip-Scale GaN Optical Devices for Near-Hysteresis-Free Hydraulic Pressure Sensing

“…As shown in Figure 5e, the response and recovery times are below 7.1 and 8.1 s, respectively, at a low loading− unloading pressure of 0−100 kPa and increase by up to 4.1 and 5.5 s with further increase in pressure. Since the optical device adopting an InGaN/GaN diode structure can provide fast transient responses in the microsecond range (see Supporting Information S8), the response and recovery times are limited 44 rGO/PPy (PDMS) 0−70 1 cm × 1 cm hydrostatic pressure porous 45 multiwalled CNTs (PDMS) 0−50 <5 centimeter scale pressure 3D microporous 46 CNT (PDMS) 0−100 7.3 7 mm × 7 mm pressure 3D porous 47 polypyrrole (PDMS) 0∼100 2 pressure microporous 48 only PDMS 0−210 2.8 circle diameter = 35 mm pressure 0−1000 micropyramid 42 Pt/BOPP (PDMS) by the hydraulic loading and unloading operation supplied by the load machine. The stability test is performed by applying cyclic loading and unloading pressure to the device.…”

Flexible pressure sensors via engineering microstructures for wearable human-machine interaction and health monitoring applications

“…One method is to coat conductive polymer composite precursor on a particular structure constructed by the sacrificial template, and then immerse it in the etching solution to remove the porogen after curing to sacrifice the template, thereby obtaining the porous conductive polymer composite with the desired structure. For example, Jung et al uniformly mixed sugar with CNT and pure sugar, respectively (Jung et al, 2021). Then, the CNT/sugar, bare sugar, and CNT/sugar were stacked in sequence in the master mold, and treated in an oven to form a sugar cube (Figure 5C).…”

“…Continued (C) Schematic of the fabrication procedure of capacitive pressure sensor with three-dimensional and porous structure by removing sugar template and pressure-response curves for the sensor. Adapted with permission(Jung et al, 2021). Copyright 2021, American Chemical Society.…”

Highly Robust Electronic Skin based on Carbon Nanomaterials and SEBS for Object Recognition of Robot Hand: Proximity and Pressure Sensing Array

“…For piezoresistive sensors, the common sensitive materials are mainly carbon nanomaterials. Carbon nanomaterials commonly include carbon nanotubes (CNT) [22], graphene [23] and MXene [24]. Because of its good mechanical exibility, stable physical and chemical properties, it has become a common material for exible piezoresistive sensors.…”