同轴湿纺炭黑-硅胶复合内涂层柔性纤维应变传感器

通过同轴湿纺技术制备了一种多层中空结构的柔性纤维应变传感器.外层是由硅胶(Ecoflex)材料制成的弹性基底层,内层是由炭黑/聚二甲基硅氧烷(CB/PDMS)复合材料制成的导电层.中空结构由CB/PDMS/CHC13混合物受热时CHC13挥发所致.同时由于CB/PDMS复合材料涂层产生了裂纹结构,增强了该中空纤维的应变...     

基于导电织物的关节弯曲角度测量传感器

柔性电容式拉伸传感器,可用于测量关节弯曲和肌肉拉伸等人体动作,具有低功耗,线性度高等优点,作为新一代可穿戴传感器在运动检测、医疗康复领域具有广泛应用前景。但现有电容式拉伸传感器存在应变灵敏度(Gauge Factor, GF)不高的缺点,导致在关节微小弯曲测量方面精度较低。针对此,提出了一种基于无机硅胶和导电织物的分段式结构柔性电容式应变传感器。传感器采用不同杨氏模量硅胶设计了非线性结构的介电弹性体,并以柔性导电布作为电极。同时,建立了传感器的关节弯曲角度感知模型。实验结果表明,该传感器由于采取了分段式结构设计,因此稳定性好,提高了在中等应变情况下(0～50%)的应变灵敏度因素(GF=1.5)。将其安装于手套上测试,弯曲角度预测模型能够对关节弯曲角度进行较好的预测。该柔性电容式应变传感器制作工艺简单,可低成本大规模制造。其分段式结构设计与角度传感模型适用于医疗康复训练和机器人操控等创新应用。     

碳纳米管/PDMS复合材料柔性阵列压力传感器制备与实验

以碳纳米管（CNTs）作为导电填料,聚二甲基硅氧烷（PDMS）为基体材料,采用溶液法制备出CNTs/PDMS导电复合材料。研究了碳纳米管浓度对复合材料的电学特性和压阻特性的影响规律,得到碳纳米管在PDMS中的渗滤区域。通过复合材料的压力灵敏度优化碳纳米管浓度。以制备的复合材料为敏感材料,FPCB工艺加工的柔性基板为电极,设计制备了一种简单结构和工艺的柔性阵列压力传感器。用零电势法设计了阵列电阻读出电路与LabVIEW实现的上位机配合,实现信号读取和显示。最后通过一个应用实例表明,该柔性阵列压力传感器及信号处理系统可以实现压力分布与大小的实时监测,可为柔性阵列压力传感器设计与制备提供参考。     

基于激光直写的柔性电阻抗成像传感器研究

基于柔性导电薄膜的电阻抗成像技术能够实现对外界刺激的二维可视化传感,在结构健康监测、人机交互、人体体征监测等领域具有广泛的应用前景。然而,现有的柔性导电薄膜多采用喷涂、浸涂和填充等方法来制备,需获取均匀分散导电浆料、且步骤较为复杂。采用激光直写技术这一高效、可规模化的加工方法,制备了一种新型柔性石墨烯导电薄膜用于电阻抗成像技术。通过调节激光焦点偏距优化了石墨烯传感器的电学性质各向异性。基于激光直写的柔性石墨烯电阻抗传感器可以用于空间裂纹、空间圆孔和筒体撞击的损伤监测。研究结果表明：该传感器可以实现空间损伤监测,最大定位误差为5.3%,最小面积比例估计误差为8.3%,在结构健康监测领域具有广阔的应用前景。     

基于 ＧＮＰｓ/ ＰＤＭＳ 复合薄膜的柔性压阻传感器制备及性能研究

目前柔性压力传感器已被用于众多领域,其中压阻薄膜是柔性压力传感器的核心。本文将石墨烯纳米片（GNPs）与聚二甲基硅氧烷（PDMS）复合,通过倒模的方法制备压阻薄膜,经测试,GNPs浓度为8%时,材料具有较好的性能。以此为基础,制备了压敏结构间距为1.2 mm,直径大小为1.0 mm的GNPs/PDMS基压阻传感器,经测试,所制备的传感器加载响应为340 ms,卸载响应速度为260 ms,并具有较好的稳定性,同时,基于该压阻式柔性压力传感器实现了人体手腕关节处压力信号的测试。     

石墨烯柔性压力/应变传感器的研究进展

柔性压力/应变传感器可以贴附在物体表面,测量其表面压力或应变,可用于人体脉搏检测、表情识别和运动监测等,在健康监护、医疗诊断等方面有广阔的发展空间.石墨烯柔性压力/应变传感器比普通压力/应变传感器性能更为优异,其测量范围宽、灵敏度高且尺寸仅为纳米级.综述了石墨烯压力/应变传感器在近几年来的研究进展及应用情况,重点讨论了基于石墨烯材料的电容法、激光诱导法、3D海绵法、纸基法、水凝胶法的压力/应变传感器的制备方法及性能差异.最后简要指明石墨烯柔性压力/应变传感器未来的研究方向.     

中国微米纳米-微纳结构对电容式柔性压力传感器性能影响的研究

设计制备出三明治结构的电容式柔性压力传感器,并对其性能进行研究.该传感器以银纳米线为电极材料,聚二甲基硅氧烷(PDMS)为柔性衬底,同时采用毛面玻璃和光面玻璃分别作为柔性衬底的制备模板,制备出微纳结构和平面结构的PDMS薄膜.然后采用喷涂法制备AgNWs/PDMS复合电极,以另外一层PDMS为介电层,将两电极面对面封装,得到电容式柔性压力传感器,最后系统研究了传感器的电极微纳结构对器件性能的影响.本文研究表明,具有微纳结构的AgNWs/PDMS复合薄膜传感器的灵敏度为1.0 kPa-1,而平面结构的AgNWs/PDMS复合薄膜传感器的灵敏度为0.6 kPa-1,由此可知具有微纳结构的柔性衬底能够显著提高器件的灵敏度.     

基于导电纤维的柔性传感器研究进展

柔性传感器优良的柔韧性使其能够最大限度地实现与服装的无缝整合,在智能纺织品领域具有很高的应用价值.基于导电纤维优良的导电性和柔韧性,其已成为制备柔性传感器的重要材料之一.主要介绍了导电纤维的种类和基于导电纤维的不同柔性传感器的传感原理,分析了其在人体运动、生命体征监测及人机交互等领域的应用优势,介绍了近几年国内外基于导...     

面向人体运动检测的纸基柔性压力阵列传感器

针对制备同时具有高灵敏度和大工作范围的柔性压力阵列传感器的挑战,以无尘纸作为基底,采用石墨烯—碳纳米管导电涂料和聚二甲基硅氧烷(PDMS)进行混合作为涂层,利用PDMS的粘性与涂料的导电性进行电气连接,使用激光切割进行阵列设计,高灵敏度(3.29 kPa~(-1))、大工作范围(0～45 kPa)的压力阵列传感器研制成功,同时纸基材料不易连接的问题也得到了解决。该传感器不仅可以用于检测大幅度的肢体运动,还可以用于探测细微的人体动作。由于该传感器具有柔软、灵敏度高、制造工艺简便、成本低、电气连接简便等优点,显示了其在可穿戴传感器领域和智能机器人触觉领域的应用潜力。     

石墨烯/聚二甲基硅氧烷三维非织造结构压阻柔性压力传感器

压阻式压力传感器是可穿戴器件中的关键元件。由于优异的弹性性能,本文以三维聚酯非织造布作为基材,还原氧化石墨烯(rGO)作为活性材料,聚二甲基硅氧烷(PDMS)作为柔性材料,组装三维(3D)压阻式压力传感器。该传感器具有良好的感应特性,包括短响应时间(120ms)和微弱的迟滞性(6.8%)。此外,该压力传感器可以用于检测人体的关节以及喉咙的运动情况。因此,该压阻传感器成本低、灵敏度高、耐久性优良,可以作为穿戴智能设备的理想的三维压阻式压力传感器。     

A flexible dry micro-dome electrode for ECG monitoring

This paper describes a flexible dry electrode with micro domes on polydimethylsiloxane (PDMS) for the monitoring of electrocardiogram (ECG). The fabrication procedure of this microstructure was mainly composed of melting photoresist, double-PDMS-molding, nickel (Ni) plating and encapsulation between two thin PDMS films. To investigate the performance of the fabricated micro-dome electrode, three dry electrodes with different arrays were fabricated to conduct the contact impendence measurements. ECG signals were measured by both the standard wet electrodes (Ag/AgCl) and dry electrodes. Experimental results showed the dry electrode provided signal quality that was comparable to the standard wet electrode without the need for skin preparation or electrolytic solution. The proposed dry electrode is more comfortable, with less skin irritation and requires no conductive gel. Thus, this flexible dry micro-dome electrode could find potential biomedical applications in health monitoring.     

A flexible encapsulated MEMS pressure sensor system for biomechanical applications

 The use of pressure sensors made of conductive polymers is common in biomechanical applications. Unfortunately, hysteresis, nonlinearity, non-repeatability and creep have a significant effect on the pressure readings when such conductive polymers are used. The objective of this paper is to explore the potential of a new flexible encapsulated micro electromechanical system (MEMS) pressure sensor system as an alternative for human interface pressure measurement. A prototype has been designed, fabricated, and characterized. Testing has shown that the proposed packaging approach shows very little degradation in the performance characteristics of the original MEMS pressure sensor. The much-needed characteristics of repeatability, linearity, low hysteresis, temperature independency are preserved. Thus the flexible encapsulated MEMS pressure sensor system is very promising and shows superiority over the commercially available conductive polymer film sensors for pressure measurement in biomechanical applications. Received: 1 December 1999/Accepted: 17 August 2000     

Fabrication of wireless sensors on flexible film using screen printing and via filling

Wireless sensors are fabricated on flexible plastic films by means of screen printing and via-hole filling. The wireless sensors are battery free with data and power transmission functions. The sensors, fabricated on polyethylene terephtalate films, are designed based on RFID technology. Using an additive patterning process known as screen printing, metallization on polymer films is created. Both sides of a polymer film are printed with metallic patterns and connected with micro vias filled with conductive paste. One side of the film consists of printed electrical traces for discrete components like resistors and transistors that would be mounted onto it; the other side consists of a printed inductive coil used for wireless data and power transmission. The micro vias, which have a diameter of 120 μm, are formed by mechanical punching and filled with conductive silver paste. The size of one sensor unit is approximately 2 cm × 1.5 cm; an array of 4 × 7 sensor units are printed over an area of 15 cm × 15 cm on a PET film. Details of manufacturing processes, component assembly and functionality test are presented in this paper.     

A flexible dry electrode based on APTES-anchored PDMS substrate for portable ECG acquisition system

We developed a simple and low-cost flexible dry electrode with micro domes by depositing metal film directly on (3-aminopropyl)triethoxysilane (APTES)-anchored polydimethylsiloxane (PDMS) substrate for portable electrocardiogram (ECG) acquisition system. However, the adhesion between metal and PDMS was poor, and metal film on PDMS always exhibited wrinkles. To overcome these difficulties, before depositing Cu, PDMS substrate was treated by APTES aqueous solution. Then, we evaluated the metal film through the microscopic photographs, the surface roughness measurements and the adhesion tests. On the base of the deposition technique improvement, a PDMS-based dry electrode for ECG monitoring was fabricated. We studied the performance of the flexible dry electrode and the results showed the fabricated electrode produced good ECG signals with distinct P, QRS, and T waves. In addition, the fabricated flexible dry electrode with micro domes showed lower skin-contact impedance and could obtain ECG signals with higher SNR than the flat dry electrode.     

Capacitive flexible pressure sensor: microfabrication process and experimental characterization

Kapton-based flexible pressure sensor arrays are fabricated using a new technology of film transfer. The sensors are dedicated to the non-invasive measurement of pressure/force in robotic, sport and medical applications. The sensors are of a capacitive type, and composed of two millimetric copper electrodes, separated by a polydimethylsiloxane (PDMS) deformable dielectric layer. On the flexible arrays, a very small curvature radius is possible without any damage to the sensors. The realized sensors are characterized in terms of fabrication quality. The inhomogeneity of the load free capacitances obtained in the same array is ±7 %. The fabrication process, which requires 14 fabrication steps, is accurate and reproducible: a 100 % transfer yield was obtained for the fabrication of 5 wafers gathering 4 sensor arrays each (215 elementary sensors). In the preliminary electro-mechanical characterization, a sensor (with a PDMS dielectric layer of 660 μm thickness and a free load capacitance of 480 fF) undergoes a capacitance change of 17 % under a 300 kPa normal stress.     

Tactile sensors based on conductive polymers

This paper presents results from a selection of tactile sensors that have been designed and fabricated. These sensors are based on a common approach that consists in placing a sheet of piezoresistive material on the top of a set of electrodes. We use a thin film of conductive polymer as the piezoresistive material. Specifically, a conductive water-based ink of this polymer is deposited by spin-coating on a flexible plastic sheet, giving it a smooth, homogeneous and conducting thin film. The main interest in this procedure is that it is cheap and it allows the fabrication of flexible and low cost tactile sensors. In this work, we present results from sensors made using two technologies. Firstly, we have used a flexible printed circuit board (PCB) technology to fabricate the set of electrodes and addressing tracks. The result is a simple, flexible tactile sensor. In addition to these sensors on PCB, we have proposed, designed and fabricated sensors with screen-printing technology. In this case, the set of electrodes and addressing tracks are made by printing an ink based on silver nanoparticles. The exhaustive characterization provides us insights into the design of these tactile sensors.     

A study on a hybrid structure flexible electro-rheological microvalve for soft microactuators

In order to realize a fluidic soft microactuator with a built-in control valve, this paper presents a cantilever type flexible electro-rheological microvalve (FERV) with a hybrid flow channel structure made from polydimethylsiloxane (PDMS) and SU-8. The hybrid structure provides high flexibility with the PDMS structure while only slight expansion occurred under high pressure with the SU-8 structure. In addition, its flexible electrodes are realized by UV-curable PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) that is a flexible conductive polymer and can be fabricated by simple and fast fabrication process without high-cost equipment. The proposed FERV can control the flow rate of the electro-rheological fluid (ERF) through the flow channel by changing its apparent viscosity with an applied electric field. FEM simulations were conducted to demonstrate the flexural rigidity of the designed FERV and compare it with the previous FERVs. Developing micro-electro-mechanical systems (MEMS) processes using the photolithography technique, the FERV was successfully fabricated and its characteristics were experimentally clarified. The results showed the feasibility of the proposed FERV in the soft microactuator application.

     

基于EIT技术的柔性触觉传感器的设计

随着机器人技术的日益发展,柔性传感器在机器人皮肤上的应用也得到了新的发展。本文提出并研究了一种基于导电聚合物压敏电阻效应的柔性触觉传感器的设计,使用由聚二甲基硅氧烷PDMS（Poly Di Methyl Siloxane）和多壁碳纳米管（MWCNTs）混合而成的导电橡胶作为传感器主体,运用EIT（Electrical Impedance Tomography）技术,设计并制作了本系统的硬件电路,并用其检测、传输导电橡胶的边缘电势数据。最后在计算机中应用工具包EIDORS进行有限元模型和图像重构技术,有效且直观的将导电橡胶上的受力位置表现出来。实验对1~3个目标分别进行了成像,证明了本设计的可行性。     

Design and fabrication of a micropatterned polydimethylsiloxane (PDMS) light‐guide plate for sheet‐less LCD backlight unit

Abstract— A polydimethylsiloxane (PDMS) light‐guide plate (LGP) having micropatterns with an inverse‐trapezoidal cross section was developed for a sheet‐less LCD backlight unit (BLU). The micropatterned PDMS LGP was fabricated by backside 3‐D diffuser lithography followed by two consecutive PDMS replication processes: photoresist‐to‐PDMS and PDMS‐to‐PDMS replications. The fabricated LGP showed an average luminance of 2878 nits and a uniformity of 73.3% in a 2‐in. backlight module with four side‐view 0.85‐cd LEDs. It also could feasibly be applied to a light source for flexible displays owing to the flexible characteristic of the PDMS itself.