Fundamental research on the effective contact area of micro-/nano-textured surface in triboelectric nanogenerator
Fundamental research on the effective contact area of micro-/nano-textured surface in triboelectric nanogenerator
复制标题
DOI：
10.1016/j.nanoen.2018.12.029
复制
发表时间：
2019-03
期刊：
影响因子：
17.6
通讯作者：
Weixu Yang;Xiaoli Wang;Hanqing Li;Jun Wu;Yanqiang Hu;Zhihao Li;Hui Liu
中科院分区：
文献类型：
--
作者：
Weixu Yang;Xiaoli Wang;Hanqing Li;Jun Wu;Yanqiang Hu;Zhihao Li;Hui Liu
纳米摩擦电发电机是一种利用接触起电和静电感应将机械能转化为电能的新型能源技术。提高TENG发电量的有效途径是通过在接触表面上引入微/纳米织构来增加有效接触面积。然而，微/纳米织构的“有效”接触面积的定义和定量分析仍存在疑问，使得通过表面织构设计来提高TENG的产量缺乏理论依据。本文建立了考虑织构的粘着接触模型，采用不精确牛顿法、双共轭稳定化（Bi-CGSTAB）法和快速傅里叶变换（FFT）等计算方法，定量分析了作用力和织构尺寸对有效接触面积和开路电压的影响。另一方面，采用光刻、湿法刻蚀和复制技术制备了金字塔形TENG织构表面，搭建了TENG接触面积和电输出测试平台，并对仿真结果和实验结果进行了比较。结果表明：（1）金字塔织构的四边都参与了接触起电，因此当接触只发生在织构区时，有效接触面积应为金字塔侧面接触面积之和;当接触同时发生在织构区和平面区时，有效接触面积应为金字塔侧面接触面积和平面接触面积之和。其次，在较轻载荷下，由于接触面积的增大，金字塔织构TENG的开路电压增大;而在较重载荷下，由于接触面积不变，TENG的开路电压保持稳定。此外，TENG的接触面积和开路电压将在较轻的作用力下随着织构间距的增加而增加，而在较重的作用力下随着织构间距的增加而减小。该研究揭示了具有织构表面的TENG接触面积与电性能之间的相关性，为TENG的织构设计提供了理论依据。
The triboelectric nanogenerator (TENG) is a new energy technology to convert mechanical energy into electricity based on contact electrification and electrostatic induction. An effective way to improve power generation of TENG is to increase the effective contact area through introducing micro-/nano-textures onto the contact surface. However, the definition and quantitative analysis on the “effective” contact area of micro-/nano-textures is still in doubt so that the design of surface texture to improve the output of TENG is lack of theoretical basis. In this paper, an adhesive contact model considering textures is established, and the computational methods such as inexact Newton method, bi-conjugate stabilized (Bi-CGSTAB) method and fast Fourier transform (FFT) technique are employed to quantitatively analyze the effects of applied force and texture size on the effective contact area and open-circuit voltage. On the other hand, the pyramid textured surfaces of TENG are fabricated through lithography, wet etching and replication techniques, the test platforms of contact area and electrical output for TENGs are constructed as well, and results from simulation and experiment are compared at last. It is shown that, firstly, the four sides of pyramid texture are involved in the contact electrification and therefore the effective contact area should be the sum of the pyramid lateral area involved in contact when contact only happens in texture region, or the sum of pyramid lateral area and flat area involved in contact when contact happens in both texture and flat regions. Secondly, under lighter loading, the open-circuit voltage of TENGs with pyramid textures increases due to the increase of contact area, while under heavier loading, the open-circuit voltage remains stable due to the unchanged contact area. In addition, the contact area and open-circuit voltage of TENGs will increase with increased texture pitch under lighter applied force while decrease with increased texture pitch under heavier applied force. This study reveals the correlation between the contact area and electrical performance of TENG with textured surfaces and provides theoretical basis for texture design of TENG.