摘要
作为可穿戴电子器件的重要分支,柔性压力传感器在人机交互、健康监测等方面具有广阔的应用前景。随着新型材料与新的器件制备策略的不断开发,柔性压力传感器的力学与电学性能不断被优化以适应不同的应用需求。相较于其他传感器,电容式柔性压力传感器具有灵敏度高、功耗低、响应快的优势。电容式柔性压力传感器的性能优化主要通过改变器件的结构参数来实现,如电极有效正对面积、电极间距、有效介电常数等。主要方法策略包括新型纳米材料的应用、新型微结构设计和新型复合材料的开发。主要优化原理有四种:(1)通过改变电极表面粗糙度来改变电极有效正对面积;(2)在电极或介电层中引入空气层以降低弹性模量;(3)在介电层中引入空气或高介电常数材料来改变有效介电常数;(4)通过复合材料在介电层中形成微电容以改变总体电容变化。在电容式柔性压力传感器的性能优化研究中存在一个共性问题,即高灵敏度与宽检测范围之间总是存在一种制约关系。在一定压力范围内,尤其是低压范围,灵敏度提升往往会使器件较易达到压缩饱和而使检测范围有限,即线性度较差。近年来,研究者们着眼于高灵敏度与宽检测范围之间的制约问题,对介电层的梯度结构设计及混合响应机制进行探索,取得了丰硕的成果,在保证高灵敏度的前提下大幅提升了器件的检测范围。然而,迟滞、稳定性及阵列优化仍是电容式柔性压力传感器面向实际应用时存在的问题。本文系统归纳了电容式柔性压力传感器的性能优化原理,分别对电极和介电层的结构设计与材料优化方法进行了介绍,分析了电容式柔性压力传感器在性能优化研究中面临的难题,并进行了展望,以期为设计和制备满足应用需求条件的高性能柔性压力传感器提供参考。
Flexible pressure sensors are an important branch of wearable electronics,which have extensive prospects for applications in human⁃machine interface and health monitoring.The electrical and mechanical properties of flexible pressure sensor are rapidly being improved to meet various application requirements following the development and application of advanced materials and new device preparation strategies.Capacitive flexible pressure sensors are superiorto other forms of flexible pressure sensors because of their high sensitivity,low power consumption,and fast response.The performance of capacitive flexible pressure sensors can be optimized by changing device structure parameters,such as effective electrode area,electrode distance,effective dielectric constant,etc.The main improvement approaches are using novel nano⁃materials,adopting new micro⁃structure designs,and developing advanced composite materials.There are four basic optimization principles:(i)increasing the efficient surface area by increasing the electrode surface roughness;(ii)introducing air to obtain a low elasticity modulus of the electrode or dielectric layer;(iii)optimizing the effective dielectric constant by introducing air or fillers;(iv)producing micro⁃capacitors to influence the overall capacitance change of the device.Maintaining high sensitivity over a broad pressure range remains a critical challenge in flexible capacitive pressure sensor research.Devices with ultra⁃high sensitivity can easily reach compression saturation under a certain pressure.The saturation limits the detection range,resulting in poor linearity.Some recent studies have focused on improving the sensitivity and detection range of flexible capacitive pressure sensors.Gradient structure design and application of hybrid mechanisms have been demonstrated to be effective methods for obtaining a wide detection range without sacrificing sensitivity.However,hysteresis,stability and array optimization are additional problems confronting the practical application of ca
作者
田玉玉
何韧
吴菊英
钟卫洲
张凯
TIAN Yuyu;HE Ren;WU Juying;ZHONG Weizhou;ZHANG Kai(Institute of Systems Engineering,China Academy of Engineering Physics,Mianyang 621999,Sichuan,China)
出处
《材料导报》
CSCD
北大核心
2023年第16期9-22,共14页
Materials Reports
基金
国家自然科学基金(12172344)。
关键词
柔性压力传感器
电容式
微结构设计
复合材料
多级结构
混合响应
flexible pressure sensor
capacitive
microstructure design
composite materials
gradient structure
hybrid response
