微结构构筑方式对柔性传感器性能的影响

设计了一种以聚二甲基硅氧烷/短切碳纤维(PDMS/SCF)复合材料为基材的柔性传感器,并通过在传感元件表面构筑的微结构阵列,实现了传感器的高灵敏度。通过模拟发现,V槽形微结构电阻对压力变化的响应性明显大于半球形微结构,并详细阐述了V槽形微结构阵列结构传感器的设计思路、结构特点、工作原理及制备流程。按照实验设计对PDMS薄膜传感器的性能等方面展开了系统的研究。测试结果表明,随着SCF含量的增加,传感器的灵敏度逐渐增加。当SCF含量为10%时,该V槽形微结构阵列柔性传感器的灵敏度为-0.72/kPa,比非结构化传感器的灵敏度高29倍,具有较高的可靠性,为柔性传感器提供了一种新的设计方案。     

基于银/石墨烯纳米复合材料的柔性压力传感器——材料制备和微纳结构构建

柔性压力传感器是柔性可穿戴设备的核心部件,在医疗保健、运动健身、安全生产等领域极具应用潜力。二维材料石墨烯具有高载流子迁移率、超大比表面积和超高机械强度,被视为制备柔性压力传感器的优良敏感材料。然而石墨烯碎片引入晶界或堆叠等缺陷,用纯石墨烯制备柔性压力传感器存在灵敏度低、稳定性差、响应范围窄等问题。将零维银纳米颗粒或一维银纳米线与石墨烯构建复合材料,可有效跨越缺陷或搭接相邻片层,起到“桥梁”作用,石墨烯片层平铺到纳米银导电网络之间,起到“补丁”作用。本文综述了用于柔性电阻式压力传感器的银/石墨烯复合材料制备方法和工艺,并介绍了不同微纳结构的传感器构建方法。     

基于热压印—半固化法制备V-cut结构柔性电阻式压力传感器

现代传感器领域中,由于柔性传感器的稳定性较高,量程较广,且具有良好的变形能力等特点,逐渐成为研究的热点,结合柔性传感器应用中提升灵敏度和减小误差值的要求,采用差温热压印方法以及半固化封装工艺,以聚二甲基硅氧烷(PDMS)为基体,内部填充高电导率材料碳纤维(SCF)和碳纳米管(CNT)制备一种新型PDMS/SCF/CNT...     

NaCl颗粒对多孔PDMS薄膜构建柔性传感器灵敏度和响应特性的影响

通过在PDMS膜中加入Na Cl微米颗粒形成孔结构,制得以多孔PDMS膜构建的柔性电容传感器,测试了不同Na Cl质量分数下的灵敏度,同时对系统耐久性与响应速率进行了分析。结果表明,纯PDMS薄膜形成了较为光滑的表面,加入Na Cl颗粒的薄膜形成了大量的孔隙结构。Na Cl颗粒质量分数为20%的多孔传感器的灵敏度为0. 68 k Pa-1,相对于无孔PDMS薄膜传感器得到显著改善。当压力增大时,灵敏度减小。对颗粒进行更长时间研磨后得到更小粒径,获得更高的薄膜传感器灵敏度。孔结构能够促进薄膜传感器对外界压力形成更明显的数值反馈。当对传感器施加5. 0 Pa压力后,传感器实现了4 s以内的响应时间,可满足快速反应的要求。压力施加与去除的迟滞变化曲线基本重合,传感器只存在很低的迟滞。传感器弯曲前后灵敏度基本一致。     

室温溶液制备半嵌入银纳米线复合透明电极

采用室温下聚合物溶液一步降阻工艺，在裸银纳米线电极表面涂覆羟乙基纤维素（HEC）溶液，制备了纤维素银纳米线复合透明电极（HEC-AgNWs-PET）。通过SEM、AFM、UV-Vis等对电极表面形貌和性能进行了表征与测试。结果表明，在裸银纳米线电极表面涂覆质量分数为0.50%的HEC溶液后，将电极（透光率为87.7%）的初始薄层电阻从27 Ω·sq-1降低至14 Ω·sq-1，而对透光率几乎无影响。HEC溶液形成的纳米膜降低了电极表面粗糙度。复合电极在12 d的加速降解测试中表现出优异的电化学稳定性，并且在2400次内外弯曲测试中，其阻值分别变为1.35和1.45倍，远小于裸银纳米线电极的阻值变化量。     

我国科学家研获高性能柔性有机太阳能电池

<正>南开大学化学学院陈永胜教授团队成功制备同时具有高导电、高透光且低表面粗糙度的银纳米线柔性透明电极,将其用于构筑柔性有机太阳能电池,光电转化效率刷新了文献报道的柔性有机/高分子太阳能电池光电转化效率的最高纪录。这一成果使得高效柔性有机太阳能电池距离实现产业化更近一步。11月4日,国际顶级学术期刊《自然·电子学》介绍了他们在柔性透明电极与柔性有机太阳能电池领     

基于微压印技术的柔性传感器的设计及制备

柔性传感器由于具有柔性、轻薄、力学性能优良且能与弹性被检测保持同步形变等优点,被广泛应用。由于聚二甲基硅氧烷(PDMS)聚合物具有高弹性、疏水性、防水性、加工性能较好,且易与多种材质在室温下结合等特点,提出了基于微压印技术及空间限域强制组装原理(SCFNA),以PDMS为基底,碳纤维(SCF)/碳纳米管(CNT)为导电填充填料,分别制成V槽微结构和平面2种结构的导电薄膜,以面对面的接触形式,采用PDMS薄膜将其封装成聚合物基柔性传感器。研究结果表明,在0～50 N范围内,聚合物基柔性传感器输出电阻与压力具有良好的线性响应特性,灵敏度能达到-27. 2Ω/N,重复性误差小于5. 5%,对传感器施压200次后,进行测试,稳定性误差小于6%。     

单根纳米线电极的制备与表征

对多元醇法合成银纳米线的反应条件进行优化,合成了长度为30μm左右、直径约为200 nm的银纳米线。通过简单的靠取法在碳纤维电极表面靠取单根银纳米线以制备纳米电极,并对其形貌、电化学性能和单细胞插入能力进行表征。结果表明,其具有合适的尺寸、优异的电化学性能和良好的机械性能,不仅促进了纳米电极的发展,还为单细胞分析提供了一种极具潜力的纳米工具。     

基于PDMS的柔性压阻式传感器的研究进展

近年来,以聚二甲基硅氧烷(PDMS)为主体材料的柔性压阻式传感器的发展十分迅速,在人体运动及健康监测、电子皮肤、智能机器人等领域中具有广阔的应用前景。本文首先介绍了柔性压阻式传感器的传感机理及主要性能指标,然后重点综述了基于PDMS的柔性压阻式传感器的研究进展,特别是在PDMS与不同导电填料结合制备传感器以及微结构构建两个方面进行了详细阐述,最后指出了当前该领域存在的一些问题,并对其发展方向进行了展望。     

基于导电涂层微结构TPU柔性传感器的制备和性能

将具有表面微结构和平整的热塑性聚氨酯（TPU）传感基片封装成压阻型柔性压力传感器，其中前者（尺寸为10 mm×10 mm）的表面喷涂不同质量（0.02、0.05、0.1 g）的多壁碳纳米管（MWCNTs），并对微结构柔性传感基片表面形貌及传感器性能进行了表征和分析。结果表明，微结构传感基片表面上微柱顶面形成一定厚度的MWCNTs层，层内MWCNTs形成网络；喷涂较高MWCNTs质量时，传感器具有较高的灵敏度和较低的检测限，这归因于压力所致MWCNTs的网络搭接程度和传感基片间接触面积的增加量较大；喷涂0.1 g MWCNTs时，传感器的灵敏度为0.143 kPa^-1（0~3 kPa），检测限低至100 Pa，在较宽压力范围内（3~200 kPa）仍有一定的压阻响应，能在4 000次的循环压缩/释放测试（峰值压力约200 kPa）中保持稳定的压阻响应，且可准确检测典型人体运动所产生的压阻响应，具有应用于智能穿戴领域的潜能。     

A Skin-Inspired Triboelectric Nanogenerator with an Interpenetrating Structure for Motion Sensing and Energy Harvesting

Rapid advancements in wearable electronics impose the challenge on power supply devices. Herein, a flexible single-electrode triboelectric nanogenerator (SE-TENG) that enables both human motion sensing and biomechanical energy harvesting is reported. The SE-TENG is fabricated by interpenetrating Ag-coated polyethylene terephthalate (PET) nanofibers within a polydimethylsiloxane (PDMS) elastomer. The Ag coating and PDMS are performed as the electrode and dielectric material for the SE-TENG, respectively. The Ag-coated PET nanofibers enlarge the electrode surface area, which is beneficial to increase sensing sensitivity. The flexible SE-TENG sensor shows the capability of outputting alternating electrical signals with an open-circuit voltage up to 50 V and a short-circuit current up to 200 nA in response to externally applied pressure. It is used to sense various types of human motions and harvest electric energy from body motion. The harvested energy can successfully power wearable electronics, such as an electronic watch and light-emitting diode. Therefore, the as-prepared SE-TENG sensor with a pressure response and self-powered capability provides potential applications in wearable sensors or flexible electronics for personal healthcare and human–machine interfaces.     

One-step elaboration of flexible transparent conductive electrodes from silver nanowires/polymer nanocomposites

A new simplified low temperature deposition method to manufacture flexible transparent conductive electrodes (FTCE) based on conductive polymer composite filled with silver nanowires (AgNWs) was investigated. Polyurethane/AgNWs composite was deposed on a poly(ethylene terephthalate) substrate as a conductive paint in a thin layer lower than 2 μm. The high aspect ratio nanowires influence on the electrical behavior is followed with surface resistivity and optical transparency experiments. The best compromise was obtained with a conductive layer filled with 2.84 vol.% of AgNWs; it exhibits a surface resistivity of 143 Ω/sq with 73% in transmittance. These transparent conductive composites processing in one step with good touching manipulation resistance demonstrate the real interest for this kind of FTCEs technology without indium tin oxide.     

Silver nanowire network embedded in polydimethylsiloxane as stretchable,transparent, and conductive substrates

Highly stretchable transparent conductors where Ag nanowire networks (AgNWs) are reliably embedded into a polydimethylsiloxane (PDMS) substrate are presented. In spite of the weak physical and chemical interaction between Ag nanowires and PDMS, a significantly high transfer efficiency and uniform embedding of AgNW percolation mesh electrodes into PDMS was achieved by simply coating aerogels onto the AgNWs and using water‐assisted transfer. By the failure‐free transfer and reliable bonding with the substrate, the conductive PDMS with embedded AgNWs that exhibits a sheet resistance (R_s) of 15 Ω/sq and 80% optical transmittance (T) are reported here. The PDMS films accommodate tensile strains up to 70% and a cyclic strain of 25% for more than 100 cycles, with subsequent R_s values as low as 90 and 27 Ω/sq, respectively. The T of this conductive PDMS is more than 25% higher than that of networks of CNTs, Cu nanowires, and hybrid composites of CNTs and graphene embedded in elastomer films such as PDMS, polyurethane, and Ecoflex. The simple and reproducible fabrication allows the extensive study and optimization of the stretchability of the meanders in terms of humidity, thickness, and substrate. The results provide new insights for designing stretchable electronics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43830.     

Investigating the effect of silver nanorods embedded in polydimethylsiloxane matrix using nanoindentation and its use for flexible electronics

The stretchable electrodes with excellent flexibility, electrical conductivity, and mechanical durability are the most fundamental components in the emerging and exciting field of flexible electronics. This article proposes a method for fabrication of such a stretchable electrode by embedding silver nanorods (AgNRs) into a polydimethylsiloxane (PDMS) matrix that is grown by a unique glancing angle deposition technique. The surface, mechanical, and electrical properties of PDMS are significantly changed after embedding the AgNRs in it. The results show that surface roughness and polarity increase after AgNRs are embedded in the PDMS matrix. Elastic modulus (E) and hardness (H) decrease with an increase in the indentation load as a result of the indentation depth effect. Due to strong interfacial adhesion of AgNRs embedded in the PDMS matrix, the E and H of nanocomposite are increased by 167.6 and 93.3% compared with PDMS film, respectively. Furthermore, the AgNRs-PDMS film has an electrical resistivity value in the order of 10⁻⁷ Ωm. It remains conductive during various mechanical strains such as bending, twisting, and stretching, which is demonstrated using a light-emitting diode circuit. Simultaneously, the antimicrobial activity of silver could make it a promising candidate for wearable electronics.     

PDMS对丁苯胶表面性能的影响

将不同相对分子质量的聚二甲基硅氧烷(PDMS)加入到丁苯橡胶(SBR)中,研究了PDMS的相对分子质量、添加量对SBR的硫化特性和纯胶硫化胶的表面性质与力学性能的影响。结果表明:加入PDMS能明显改善SBR纯胶硫化胶的表面性质,疏水性增加,PDMS相对分子质量小时(8万)效果明显;PDMS的加入对力学性能几乎无影响,硫化特性也无明显变化,焦烧时间略有增加,最大扭矩略有下降。     

Ga and Ti co-doped In2O3 films for flexible amorphous transparent conducting oxides

We designed Ga and Ti co-doped In₂O₃ (IGTO) films to use as a flexible and transparent amorphous conducting oxide electrode in thin film heaters (TFHs) and flexible touch screen panels (FTSPs) for automobiles. The properties of the IGTO electrodes deposited on cyclic olefin copolymer (COP) at room temperature were investigated as a function of the O₂/(Ar + O₂) flow ratio, to confirm the best sputtering condition for transparent and flexible electrode. Depending on the oxygen flow ratio, the IGTO/COP electrodes showed sheet resistance of (39.3 – 1.57) × 10⁴ Ohm/sq, an average transmittance of (84.90 – 87.12) % at visible wavelength area, and a surface roughness of (0.95 – 3.23) nm. In addition, IGTO/COP samples exhibited good mechanical flexibility with critical bending radius of 3 mm, which is enough to be used as FTSPs. From the previously mentioned results, we found the amorphous IGTO/COP to be a promising flexible and transparent electrode for curved TFHs and FTSPs. The flexible IGTO/COP TFHs demonstrated a saturated temperature of 78.6 °C when applied with low operating direct current (DC) of 8 V, due to its low sheet resistance. In addition, the IGTO/COP FTSPs showed very stable touch sensitivity, even at a bent state. We found that the optimized IGTO/COP is a promising flexible and transparent electrode for next-generation automobiles.     

Pt纳米粒子/ZnO纳米管修饰的钛片葡萄糖传感器

基于钛片载Pt纳米颗粒修饰的ZnO纳米管电极制备了葡萄糖生物传感器。用电化学沉积法制备了ZnO纳米棒阵列,并用化学腐蚀法制备了ZnO纳米管。Pt纳米颗粒采用恒电位沉积法修饰在ZnO纳米管表面。用扫描电子显微镜和X-射线衍射表征了纳米Pt-ZnO/Ti修饰电极。该修饰电极在0.05 M的NaOH中对葡萄糖的催化氧化表现出很好的响应,线性范围为1×10-5～1×10-2mol/L,响应时间小于4 s,并且具有良好的重现性。     

Flexible Sandwich Structural Strain Sensor Based on Silver Nanowires Decorated with Self‐Healing Substrate

Flexible and stretchable conducting composites that can sense stress or strain are needed for several emerging fields including human motion detection and personalized health monitoring. Silver nanowires (AgNWs) have already been used as conductive networks. However, once a traditional polymer is broken, the conductive network is subsequently destroyed. Integrating high pressure sensitivity and repeatable self‐healing capability into flexible strain sensors represents new advances for high performance strain sensing. Herein, superflexible 3D architectures are fabricated by sandwiching a layer of AgNWs decorated self‐healing polymer between two layers of polydimethylsiloxane, which exhibit good stability, self‐healability, and stretchability. For better mechanical properties, the self‐healing polymer is reinforced with carbon fibers (CFs). The sensors based on self‐healing polymer and AgNWs conductive network show high conductivity and excellent ability to repair both mechanical and electrical damage. They can detect different human motions accurately such as bending and recovering of the forearm and shank, the changes of palm, fist, and fingers. The fracture tensile stress of the reinforced self‐healing polymer (9 wt% CFs) is increased to 10.3 MPa with the elongation at break of 8%. The stretch/release responses under static and dynamic loads of the sensor have a high sensitivity, large sensing range, excellent reliability, and remarkable stability.     

High performance of carbon nanotubes/silver nanowires-PET hybrid flexible transparent conductive films via facile pressing-transfer technique

To obtain low sheet resistance, high optical transmittance, small open spaces in conductive networks, and enhanced adhesion of flexible transparent conductive films, a carbon nanotube (CNT)/silver nanowire (AgNW)-PET hybrid film was fabricated by mechanical pressing-transfer process at room temperature. The morphology and structure were characterized by scanning electron microscope (SEM) and atomic force microscope (AFM), the optical transmittance and sheet resistance were tested by ultraviolet-visible spectroscopy (UV-vis) spectrophotometer and four-point probe technique, and the adhesion was also measured by 3M sticky tape. The results indicate that in this hybrid nanostructure, AgNWs form the main conductive networks and CNTs as assistant conductive networks are filled in the open spaces of AgNWs networks. The sheet resistance of the hybrid films can reach approximately 20.9 to 53.9 Ω/□ with the optical transmittance of approximately 84% to 91%. The second mechanical pressing step can greatly reduce the surface roughness of the hybrid film and enhance the adhesion force between CNTs, AgNWs, and PET substrate. This process is hopeful for large-scale production of high-end flexible transparent conductive films.