Conductive Fiber-Based Ultrasensitive Textile Pressure Sensor for Wearable Electronics
Conductive Fiber-Based Ultrasensitive Textile Pressure Sensor for Wearable Electronics
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DOI：
10.1002/adma.201500009
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发表时间：
2015-04-17
影响因子：
29.4
通讯作者：
Lee, Taeyoon
中科院分区：
文献类型：
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作者：
Lee, Jaehong;Kwon, Hyukho;Lee, Taeyoon
DOI：10.1002/adma. 201500009必不可少。[26]为了确保导电纤维，已经广泛研究了各种方法，例如碳基材料的浸涂工艺[27，28]、电镀[29]和无电镀工艺[30，31]。然而，上述方法在同时获得上级电性能和稳定性的能力方面受到限制;[8，32]从电镀和无电镀工艺获得的金属基导电纤维具有优异的电性能和差的稳定性，并且在从浸涂工艺获得的碳材料基导电纤维的情况下反之亦然。最近，Lee等人展示了一种有效的化学溶液工艺，该工艺使用纤维上的铝（Al）金属前体复合材料的化学还原，形成Al纳米颗粒与它们之间的连接。[26]由于金属纳米颗粒的连接，化学溶液法可用于获得具有高电导率和耐久性的导电纤维;然而，金属纳米颗粒在没有能够结合金属前体的表面基团的特定聚合物纤维上的差的沉积效率应得到改善。[33]在这项研究中，我们描述了一种基于纺织品的压力传感器，具有前所未有的灵敏度，优异的耐用性，快速响应和弛豫时间，基于涂覆有介电橡胶材料的高导电纤维。通过在聚对苯撑二甲酰胺（Kevlar）纤维表面包覆聚苯乙烯-嵌段-丁二烯苯乙烯（SBS）聚合物，然后在SBS聚合物中直接将大量的银离子转化为银纳米粒子，制备了导电纤维。由于Ag纳米粒子之间的紧密电连接，所制备的导电纤维具有优异的电性能，其电性能可达0.15 Ω cm-1，并具有良好的抗3000次反复弯曲试验的稳定性。通过在导电纤维表面涂覆聚二甲基硅氧烷（PDMS）作为介电层，并将两层PDMS涂覆纤维垂直堆叠，成功地制备了电容式纺织压力传感器。所获得的压力传感器具有高灵敏度（0.21 kPa− 1）、毫秒级的非常快的响应时间以及超过10000次循环的高稳定性。基于纺织品的压力传感器可以通过编织方法像素化为织物形式的矩阵式压力传感器，并嵌入到手套和衣服中，作为人机界面用于无线控制机器。图1a示出了导电纤维的制造过程的示意图。该过程包括三个主要步骤：（i）在Kevlar纤维表面上涂覆SBS，（ii）将Ag前体吸收到SBS层中，以及（iii）还原Ag前体以在SBS层中形成Ag纳米颗粒。SBS聚合物可以均匀地涂覆在电子纺织品（e-textiles）上，其中各种电子元件，如传感器，[1，2]能量收集设备，[3]场效应晶体管，[4，5]和天线[6]集成到织物中，随着先进的柔性和可穿戴设备的发展，吸引了相当大的兴趣。[7，8]特别是基于纺织品的压力传感器，由于其可集成到衣服和床中，因此已被广泛探索用于各种应用，包括照顾老年人，[9]诊断，[10]监测患者，[8]和人体运动检测[11]。为了实现高性能的基于纺织品的压力传感器，各种操作类型的压力传感器，例如电容式、[12，13]压阻式、[14-17]压电式、[18，19.
DOI: 10.1002/adma. 201500009 essential.[26] To ensure the conductive fibers, various methods such as dip-coating process of carbon-based materials,[27, 28] electro-[29] and electroless-plating process [30, 31] have been extensively investigated. However, the aforementioned approaches are limited in their ability to obtain a superior electrical performance and stability at the same time;[8, 32] metal-based conductive fibers obtained from the electro-and electroless-plating process have excellent electrical properties and poor stability, and vice versa in the case of carbon material-based conductive fibers obtained from the dip-coating process. Recently, Lee et al. demonstrated an efficient chemical solution process, which uses the chemical reduction of aluminium (Al) metal precursor composites on the fibers, forming Al nanoparticles with connections between them.[26] The chemical solution process can be useful to obtain conductive fibers with high electrical conductivity and endurance due to the connection of metal nanoparticles; however, the poor deposition efficiency of metal nanoparticles on specific polymeric fibers without surface groups able to bind metal precursors should be improved.[33] In this research, we describe a textile-based pressure sensor with unprecedented sensitivity, excellent durability, a fast response, and a relaxation time based on highly conductive fibers coated with dielectric rubber materials. The conductive fibers were fabricated by coating poly (styrene-block-butadienstyrene)(SBS) polymer on the surface of poly (p-phenylene terephthalamide)(Kevlar) fiber, followed by converting a huge amount of silver (Ag) ions into Ag nanoparticles directly in the SBS polymer. The obtained conductive fibers have an excellent electrical property of 0.15 Ω cm–1 owing to the dense electrical connection of the Ag nanoparticles and the good stability against repeated external deformations of 3 000 bending tests. By coating poly (dimethylsiloxane)(PDMS) as dielectric layers on the surface of the conductive fibers and stacking the two PDMS-coated fibers perpendicularly to each other, a capacitive type of textile pressure sensor was successfully fabricated. The obtained pressure sensor exhibited high sensitivity (0.21 kPa− 1), very fast response times in the millisecond range and high stability over more than 10 000 cycles. The textile-based pressure sensor could be pixelated to matrix-type pressure sensor in the form of fabrics by using a weaving method and imbedded into gloves and clothes, which were applied to control machines wirelessly as human–machine interfaces. Figure 1a presents a schematic illustration of the fabrication procedure of conductive fibers. The procedure involves three main steps:(i) coating of SBS on the surface of Kevlar fiber,(ii) absorption of Ag precursors into the SBS layer, and (iii) reduction of the Ag precursors to form Ag nanoparticles in the SBS layers. The SBS polymer could be uniformly coated onElectronic textiles (e-textiles) where various electronic elements such as sensors,[1, 2] energy harvesting devices,[3] fieldeffect transistors,[4, 5] and antennas [6] are integrated into fabrics have attracted considerable interest with the development of advanced flexible and wearable devices.[7, 8] A textile-based pressure sensor, in particular, has been widely explored for a variety of applications to include caring for the elderly,[9] diagnostics,[10] monitoring patients,[8] and human motion detection [11] due to their integrability into clothes and beds. To realize the high-performance textile-based pressure sensor, various operation types of pressure sensors such as capacitive,[12, 13] piezoresistive,[14–17] piezoelectric,[18, 19 …