School of Mechanical and Power Engineering , East China University of Science and Technology , Shanghai 200237 , China.
ACS Appl Mater Interfaces. 2018 Oct 31;10(43):37760-37766. doi: 10.1021/acsami.8b16591. Epub 2018 Oct 16.
Stretchable strain sensors with high sensitivity or gauge factor (GF), large stretchability, and long-term durability are highly demanded in human motion detection, artificial intelligence, and electronic skins. Nevertheless, to develop high-sensitive sensors without sacrificing the stretchability cannot be realized using simple device configurations. In this work, an acid-interface engineering (AIE) method was proposed to develop a stretchable strain sensor with high GF and large stretchability. The AIE generates a layer of SiO at the interface between the carbon nanotube (CNT) film and Ecoflex, playing a key role in enhancing the sensor's GF. Compared to devices without AIE (GF = 2.4), the ones with AIE are significantly improved. At an AIE time of 10 min, the GF up to 1665.9 is achieved without sacrificing the stretchability (>100%). The AIE-generated cracks are found to modulate the electrical behaviors and enhance the GFs of sensors with AIE through the crack-induced rapid reduction in the electrical conduction pathway, which is manipulated by the CNTs bridging over the cracks. The device with AIE proves its high mechanical durability through a cycling test (>10 000 cycles) at a high strain up to ∼80%, further paving its practical applications in various human motion detections.
具有高灵敏度或应变系数 (GF)、大拉伸性和长期耐用性的可拉伸应变传感器在人体运动检测、人工智能和电子皮肤等领域有很高的需求。然而，要开发出高灵敏度的传感器而不牺牲拉伸性，仅通过简单的设备配置是无法实现的。在这项工作中，提出了一种酸界面工程 (AIE) 方法，用于开发具有高 GF 和大拉伸性的可拉伸应变传感器。AIE 在 CNT 薄膜和 Ecoflex 之间的界面生成一层 SiO2，在提高传感器的 GF 方面起着关键作用。与没有 AIE 的器件（GF = 2.4）相比，具有 AIE 的器件有显著的提升。在 AIE 时间为 10 分钟时，GF 高达 1665.9，同时保持了可拉伸性（>100%）。通过实验发现，AIE 生成的裂纹通过 CNT 桥接裂纹来调制电行为并提高具有 AIE 的传感器的 GF，从而快速减少电传导途径。该具有 AIE 的器件通过在高达约 80%的高应变下进行超过 10000 次的循环测试，证明了其具有很高的机械耐久性，进一步为其在各种人体运动检测中的实际应用铺平了道路。
