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Lightweight, Superelastic Boron Nitride/Polydimethylsiloxane Foam as Air Dielectric Substitute for Multifunctional Capacitive Sensor Applications
Author(s) -
Tay Roland Yingjie,
Li Hongling,
Lin Jinjun,
Wang Hong,
Lim Jacob Song Kiat,
Chen Shuai,
Leong Wei Lin,
Tsang Siu Hon,
Teo Edwin Hang Tong
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201909604
Subject(s) - materials science , polydimethylsiloxane , capacitive sensing , composite material , dielectric , fabrication , porosity , composite number , boron nitride , pressure sensor , capacitance , optoelectronics , electrode , mechanical engineering , medicine , chemistry , alternative medicine , pathology , computer science , engineering , operating system
Porous polymeric foams as dielectric layer for highly sensitive capacitive based pressure sensors have been extensively explored owing to their excellent flexibility and elasticity. Despite intensive efforts, most of previously reported porous polymer foams still suffer from difficulty in further lowering the attainable density limit of ≈0.1 g cm −3 while retaining high sensitivity and compressibility due to the limitations on existing fabrication techniques and materials. Herein, utilizing 3D interconnected networks of few‐layer hexagonal boron nitride foams ( h ‐BNFs) as supporting frameworks, lightweight and highly porous BN/polydimethylsiloxane composite foams (BNF@PDMS) with densities reaching as low as 15 mg cm −3 and permittivity close to that of air are fabricated. This is the lightest PDMS‐based foam reported to date. Owing to the synergistic effects between BN and PDMS, these lightweight composite foams possess excellent mechanical resilience, extremely high compressibility (up to 95% strain), good cyclic performance, and superelasticity. Being electrically nonconductive, the potential application of BNF@PDMS as a dielectric layer for capacitive sensors is further demonstrated. Remarkably, the as‐fabricated device can perform multiple sensing functions such as noncontact touch sensor, environmental monitoring sensor, and high sensitivity pressure sensor that can detect extremely low pressures of below 1 Pa.