Precise Engineering of Conductive Pathway by Frictional Direct-Writing for Ultrasensitive Flexible Strain Sensors
Precise Engineering of Conductive Pathway by Frictional Direct-Writing for Ultrasensitive Flexible Strain Sensors
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超灵敏柔性应变传感器摩擦直写导电通路的精确工程
DOI：
10.1021/acsami.7b14501
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发表时间：
2017
影响因子：
9.5
通讯作者：
Jianfeng Zang
中科院分区：
文献类型：
--
作者：
Zhikang Zeng;Yan Yu;Yongming Song;Ni Tang;Lei Ye;Jianfeng Zang
在显示器、机器人技术、疲劳检测、身体监测、体外诊断和先进治疗等领域，对能够检测微小应变的高灵敏度应变传感器有很高的需求。然而，由导电传感膜与柔性基底相结合构成的电阻式传感器存在局限，即它们在小应变（例如0.1 - 1%）时的应变系数（GF）不高。在此，通过在复合纸基底上用石墨棒进行摩擦直写，我们制造出了在小应变下具有极高应变系数的应变传感器。这些传感器在0.9%的小应变下应变系数为9720，最小应变检测可达0.05%，应变分辨率为0.05%，响应时间为40毫秒，并且具有高稳定性（>5000次弯曲 - 伸直循环）。与迄今为止的文献结果相比，我们的传感器在小应变下具有最高的应变系数值。如此高的灵敏度是由于对狭窄的二维逾渗导电路径的精确控制，这意味着导电石墨片的含量接近导电逾渗阈值。应变传感器对微变形变化有快速响应，并且通过便捷有效的设备设计安装能够监测各种结构变化，包括人体运动。
Highly sensitive strain sensors that can detect small strain are in high demand in the fields of displays, robotics, fatigue detection, body monitoring, in vitro diagnostics, and advanced therapies. However, resistive-type sensors that are composed of electrically conductive sensing films coupled with flexible substrates suffer from the limits that their gauge factors (GFs) at small strains (e.g., 0.1-1%) are not high. Herein, through frictional direct-writing of graphite rod on the composite paper substrates, we produced strain sensors with extremely high gauge factor at small strains. The sensors exhibited a gauge factor of 9720 at a small strain of 0.9%, minimum strain detection up to 0.05%, strain resolution of 0.05%, response time of 40 ms, and high stability (>5000 bending unbending cycles). Compared with the literature results so far, our sensors hold the highest GF value at small strains. Such high sensitivities are due to the precise control of narrow two-dimensional percolative conductive pathway, which means the content of conductive graphite sheets is close to the conductive percolation threshold. The strain sensors have a rapid response to microdeformation changes and can monitor various structural changes, including human motion, through facilitative and effective installation of device designs.