High-Performance Porous PDMS-Based Piezoresistive Sensor Prepared by a Modified Microwave Irradiation Process

Abstract

The flexible pressure sensor based on a porous structure has excellent sensing performance. It is critical to develop a large-scale and lowcost manufacturing method for realizing high-performance flexible sensors with porous structures. Herein, a porous polydimethylsiloxane (PDMS) was prepared by a modified microwave irradiation process, and an ultrahigh sensitive flexible piezoresistive sensor with wide sensing range was obtained by coating carbon nanotubes (CNTs)/graphene on the porous PDMS surface. Due to the uniform macroporous structure in PDMS and the synergistic conductive effect of graphene and CNTs, the sensitivity of the flexible sensor is up to 300.31 kPa −1 in 0−50 kPa and 52.51 kPa −1 in 50−200 kPa. Moreover, the flexible device has good reversibility, rapid response speed, good stability, and a certain anti-electromagnetic interference ability. The application in the monitoring of physiological signals demonstrates that the porous PDMS-based sensor prepared by the convenient and environmental microwave irradiation process has remarkable ability in monitoring human health. In addition, the modified microwave irradiation method also provides a way for the preparation of porous materials for other applications such as electromagnetic shielding materials.

Wearable flexible pressure sensors: an intriguing design towards microstructural functionalization

“…Upon the release of pressure, the porous PDMS returns to its original state due to its elasticity, leading to a reduction in the conductive pathways between the pore walls, and hence the restoration of the sensor resistance to its initial value. 190 According to Euler's critical load, the critical force at which buckling occurs is inversely proportional to the length of the thin column between pores. 192 Given that the column of larger pores is longer, buckling would occur at a relatively lower pressure.…”

“…Upon the release of pressure, the porous PDMS returns to its original state due to its elasticity, leading to a reduction in the conductive pathways between the pore walls, and hence the restoration of the sensor resistance to its initial value. 190…”

Highly Sensitive Flexible Pressure Sensors with Hybrid Microstructures Similar to Volcano Sponge

“…This is mainly because the approaches employed to create surface microstructures are different from those of porous structures. Specifically, the fabrication of microstructures on flexible substrates’ surfaces involves laser ablation, – templates, and lithography, – while the creation of porous structures of flexible substrates commonly employs the sacrificial template method, chemical foaming method, microwave heating method, and directional freezing. , Therefore, the hybrid structures composed of porous structures and surface microstructures are achieved by multistep processes, which makes the implementation of the sensor time-consuming and difficult. Thus, it is necessary to develop a new, simple, cost-effective, one-step approach to prepare hybrid structures for flexible sensors, but related studies have rarely been reported.…”

High sensitivity and wide range flexible piezoresistive sensor based on petal-shaped MOF-derived NiCo-NPC

“…Flexible piezoresistive sensors [1][2][3][4] have been widely reported recently because of their promising application in flexible electronics [5,6], motion detection [7,8], and health monitoring [1]. Flexible piezoresistive sensors possess a wide operating range, excellent sensitivity, quick response time, and exceptional repeatability.…”