Optimization a structure of MEMS based PDMS ferroelectret for human body energy harvesting and sensing

Abstract

A ferroelectret is typically a charge-storing cellular foam that demonstrates excellent piezoelectric properties making them potentially suitable for both sensing and energy harvesting applications. In this work we developed a numerical finite element analysis (FEA) model to describe ferroelectret materials and to further improve their piezoelectric properties. Using this FEA model, ferroelectret materials with rectangular and parallelogram void structure were designed and then fabricated by casting polydimethysiloxane (PDMS) in microfabricated silicon moulds. The piezoelectric properties and energy harvesting output of the fabricated PDMS ferroelectrets were both simulated and evaluated experimentally. For a single layer PDMS parallelogram void structure, the predicted piezoelectric coefficient d 33 from the ANSYS simulations is around 320 pC N −1 . The fabricated PDMS ferroelectret has a low Young's modulus of 670 kPa and a piezoelectric coefficient of 240 pC N −1 . A maximum d 33 of 520 pC N −1 was observed in a multilayer ferroelectret structure. When applying compressive forces simulating a footstep, the material demonstrated an output power of 2.73 μW when connected to a 65 MΩ resistive load.

Recent advances in film-based fluorescence sensing

“…敏感元件作为 传感器的核心部件, 如同人的感觉器官一样, 在传感检 测中起重要作用. 传感器按照敏感元件的种类不同, 大 致可以分为三大类: 生物类, 如基于酶、抗体和激素等 分子识别功能的传感器 [6,7] ; 化学类, 指基于化学反应 原理的传感器 [8] ; 物理类, 通常指基于光、电、磁、 力、热和声等物理效应响应的传感器 [9,10] . 这其中, 基于化学类的荧光化学传感器由于具备 荧光信号明显、响应速度快、操作简单等优势受到人 们的广泛关注 [11~15] .…”

Multistable vibration energy harvesters: Principle, progress, and perspectives

“…Shi et al [135] optimized of a structure of MEMS based polydimethysiloxane ferroelectret which can be used for harvesting energy from human body. Wang et al [136] used the fan-folded structure to design a compact MEH (5.28×2.54×1.73 cm 3 ), and tested its energy harvesting performance under 1 g acceleration.…”

Ferroelectrets: Recent developments

“…[74,75] Luo et al prepared an 80-layer ferroelectret energy harvesting insole, which could harvest about 100 μJ energy per footstep of a person 80 kg in weight [76,77]. Later, by using newly developed, thermally stable ferroelectrets with large longitudinal and/or transverse piezoelectricity, power outputs of up to more than 100 μW were achieved [78][79][80][81][82][83][84][85][86][87][88][89]. Zhang et al prepared radiation-crosslinked PP (IXPP) ferroelectrets with improved piezoelectric sensitivity and better thermal stability as compared with normal cellular PP ferroelectrets [78].…”

“…prepared an 80‐layer ferroelectret energy harvesting insole, which could harvest about 100 μJ energy per footstep of a person 80 kg in weight [76, 77]. Later, by using newly developed, thermally stable ferroelectrets with large longitudinal and/or transverse piezoelectricity, power outputs of up to more than 100 μW were achieved [78–89]. Zhang et al.…”