State Key Laboratory of Optoelectronic Materials and Technologies, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
ACS Appl Mater Interfaces. 2021 Mar 31;13(12):14479-14488. doi: 10.1021/acsami.0c22756. Epub 2021 Mar 19.
High-performance strain sensors, composed of various artificial sensing materials on/in stretchable substrates, show great promise for applications in flexible electronic devices. Here, we demonstrated a highly sensitive and durable strain sensor consisting of a ribbon of close-packed sea-urchin-shaped silver nanoparticles (SUSNs) sandwiched between two layers of poly(dimethylsiloxane) (PDMS). Each of SUSNs possesses high-density and spherically distributed sharp spines over the body, which promotes electron transduction and further improves signal detection. This SUSN-based sensor possesses a desirable integration of high sensitivity (a gauge factor of 60) and large stretchability (up to 25%) at tensile sensing, broadening its application in wearable devices. Moreover, it also shows fast response (48 ms), good reproducibility, and long-term stability (>2500 cycles at 20% strain). It can also be used to detect compressing (sensitivity up to 31.5) and folding-type bending deformations. The sensing mechanism, the resistance of the sensors varying as the deformation load, results from the inter-spine contacts change and the microcracks evolution caused by variation in the gap between SUSNs. The sensor's sensitivity at different degrees of strain was also achieved by controlling the width of the close-packed SUSNs ribbon. For practical demonstration, the SUSN-based sensors could be used as wearable devices for monitoring human activities ranging from subtle deformations to substantial movements.
高性能应变传感器由可伸缩基底上的各种人工感应材料组成，在柔性电子设备的应用中具有广阔的前景。在这里，我们展示了一种由紧密排列的海胆状银纳米粒子（SUSN）带夹在两层聚二甲基硅氧烷（PDMS）之间组成的高灵敏度和耐用的应变传感器。每个 SUSN 都具有高密度和球形分布的尖锐刺，促进了电子转导，并进一步提高了信号检测。这种基于 SUSN 的传感器具有高灵敏度（应变系数为 60）和大拉伸性（拉伸时可达 25%）的理想结合，拓宽了其在可穿戴设备中的应用。此外，它还具有快速响应（48ms）、良好的重现性和长期稳定性（在 20%应变下超过 2500 次循环）。它还可以用于检测压缩（灵敏度高达 31.5）和折叠弯曲变形。传感机制是传感器的电阻随变形负载而变化，这是由于刺之间的接触变化和 SUSN 之间间隙变化引起的微裂纹演化所致。通过控制紧密排列的 SUSN 带的宽度，可以实现传感器在不同应变程度下的灵敏度。为了实际演示，基于 SUSN 的传感器可用作可穿戴设备，用于监测从细微变形到大幅度运动的人体活动。
