Flexible Pressure Sensors with Combined Spraying and Self-Diffusion of Carbon Nanotubes

Abstract

High-performance wearable sensors are required for applications in medical health and human–machine interaction, but their application has limited owing to the trade-off between sensitivity, pressure range, and durability. Herein, we propose the combined spraying and self-diffusion process of carbon nanotubes (CNTs) to balance and improve these parameters with the CNTs spontaneously diffusing into the film surface before the film curing. The obtained sensor not only achieves high sensitivity (155.54 kPa–1) and ultrawide pressure detection range (0.1–500 kPa) but also exhibits exceptional durability (over 12,000 pressure cycles at a high pressure of 300 kPa). In addition, the sensor exhibits a fast response (25 ms), good stability, and full flexibility. This process is a general approach that may improve the performance of various types of thin film piezoresistive sensors. Besides, the fabricated sensors can be flexibly scaled into sensor arrays and communicate with smart devices to achieve wireless smart monitoring. At present, the sensor shows broad application prospects in the fields of intelligent medical health and motion sensing.

Advanced Functional Composite Materials toward E‐Skin for Health Monitoring and Artificial Intelligence

“…To achieve these superior properties, tremendous efforts have been devoted to the construction of functional polymer composite materials by selecting proper fillers and appropriate engineering of polymer composites. Varieties of nano-/microstructured materials such as graphene, [38] carbon nanotubes/nanowires, [39][40][41] metal particles, [42][43][44] metal nanowires, [45,46] metal oxide nanoparticles, [30,47] and polymers [48][49][50] have been extensively studied as candidate fillers in functional polymer composite. In this section, we report recent advances in the development of functional polymer composite materials with various compositions in terms of the selection criteria of the fillers and property optimization of the polymer composites.…”

“…Strain/pressure sensors are proved with the great potential in building smart human-machine interfaces. [39,227] The signals collected by the strain/pressure sensors can be used to control smart robots. Therefore, different kinds of smart gloves were developed based on wearable, stretchable, and skin-mountable strain sensors for the bending angle measurement of finger joints.…”

An ultra-tough and ultra-sensitive ionogel pressure/temperature sensor enabled by hierarchical design of both materials and devices

“…An ideal flexible pressure sensor should exhibit high sensitivity, wide threshold, fast response, and good puncture- and cut-resistance, and can be healed in case mechanical damage has occurred. 7–9 Unfortunately, such flexible pressure sensors are rarely reported in the literature. 10,11…”

“…An ideal exible pressure sensor should exhibit high sensitivity, wide threshold, fast response, and good puncture-and cut-resistance, and can be healed in case mechanical damage has occurred. [7][8][9] Unfortunately, such exible pressure sensors are rarely reported in the literature. 10,11 Ionogels integrate the advantages of non-volatility, transparency, wide-range operating temperatures, high conductivity and good electrochemical stability, endowing their suitability in pressure sensors.…”

Bioinspired Dual‐Mode Stretchable Strain Sensor Based on Magnetic Nanocomposites for Strain/Magnetic Discrimination

“…As wearable electronic devices are rapidly developing, the preparation of flexible sensors has opened up broad prospects, such as electronic skin, [1][2][3][4][5][6] health monitoring, [7][8][9][10][11][12][13][14][15][16] and intelligent robots. [17][18][19][20][21][22][23][24] Flexible sensors detect various external stimuli, including strain, pressure, and magnetic field, by monitoring the response signal.…”