SiC Nanowire Sponges as Electropressure Sensors

Abstract

Light-weight, flexible and highly porous ceramic are very attractive to engineering applications due to their good inertness, stable and excellent mechanical properties. We here report such SiC nanowire (SiCNW) sponges and demonstrate their multi-functionalities. They were simply generated by reacting SiO2 with the sustainable kitchen sugar, using NH4Cl as a blowing agent. The as-grown highly porous SiCNW sponges exhibit a core-shell structure, with an extremely low density in the range of 115-125 mg/cm 3 (against 3.21 g/cm 3 for the bulk). The core part is comprised of short and tangled SiC whiskers with SiC flakes embedded, whilst the shell layer consists of numerous smooth SiCNWs of hundred micrometres long. These sponges exhibit a compressive modulus of ~1.35 MPa and recoverability under cyclic compression loading for 100 cycles at a strain of 20%. Meanwhile, the SiCNW sponges exhibit interesting electromechanical sensing capability with a gauge factor up to 87 and stable wide-range compression-resistance responses that are hundreds of times better than those of carbon-based composite sensors. Furthermore, the high porosity (96.1% -96.4%) of sponges gives rise to a very low thermal conductivity of merely 1.01 W/mK at room temperature, demonstrating their excellent thermal insulation potential. These light-weight, highly porous, thermally insulating features of the SiCNW sponges can be further exploited in electromechanical micro-devices for monitoring structural damage or capturing impacts, at high temperature environment.

Challenges and emerging opportunities in transistor-based ultrathin electronics: design and fabrication for healthcare applications

“…In fact, conventional manufacturing of flexible functional materials, including iontronic materials, liquid metals, and conductive polymers doped with micro-/nanoparticles, inevitably results in fluctuations in their conductivity because of strain. 79–86 Hence, a thorough examination of strategies for stretch insensitivity is needed to better understand the aspects related to strain.…”

Design, Synthesis, and Use of High Temperature Resistant Aerogels Exceeding 800 oC

“…Thus, the method is relative simple, efficient, energy and material economic, and versatile. Zhu et al [156] used in-situ template and NH 4 Cl foaming method to prepare SiC foam (Fig. 7f), which was successfully used in the field of pressure sensors by virtue of its high elastic conductivity.…”

“…[194] Xia et al reported a SiC nanowire (SiCNW) sponge with low density (115 -125 mg/cm 3 ), good mechanical properties (compressive modulus of about 1.35 MPa) and electromechanical induction (gauge factor up to 87). [156] In addition, the thermal conductivity of SiCNW sponge at room temperature is low, about 1.01 W/mK, indicating that it has a certain potential to monitor structural damage or capture impact in high-temperature environments.…”

Nanoarchitectonics for Wide Bandgap Semiconductor Nanowires: Toward the Next Generation of Nanoelectromechanical Systems for Environmental Monitoring

“…[256][257][258][259][260] However, the fabrication of high-performance pressure sensors based on WBG semiconductor nanowires, especially for SiC, group III-nitrides, and diamond, are very rare. [261][262][263] For instance, Phan et al reported an effective approach to develop highly sensitive pressure sensors employing 3C-SiC nanowires fabricated at the center of a dogbone-like structure. [261] Figure 12a shows a photograph of SiC nanowire-based pressure sensors mounted on an acrylic holder.…”

“…Very recently, Chen et al., developed lightweight SiC nanowire sponges via the simple sugar‐blowing‐assisted carbothermal reduction. [ 262 ] Their experimental results showed an excellent pressure‐dependent electrical response. The electrical resistance decreased with the rise of the applied load but completely recovered upon unloading (Figure 12e).…”