Flexible strain sensors play a crucial role in health monitoring, smart wearable devices, and human–machine interaction. Three-dimensional surface evaluation methods for strain sensors offer advantages by being closer to actual strain, featuring a larger working range, and being more suitable for multidirectional strain. In this study, a three-dimensional (3D) surface strain sensor based on polydimethylsiloxane/laser-induced graphene (PDMS/LIG) composite films has been developed. The electromechanical properties of this sensor, encompassing 3D strain range and sensitivity, can be adjusted by manipulating laser parameters and LIG patterns. The key to attaining these specific characteristics lies in the intentional design of crack types and orientations on the sensor's surface. Remarkably, the line-vertical (LV) sensor exhibits outstanding sensitivity with a GF of 211.3. The line-parallel (LP) sensor achieves a GF of 115.1. Additionally, it demonstrates a stretching range of 25% and maintains stable performance over an extensive number of strain/release test cycles (more than 3000 cycles). With these advantages, the 3D strain sensor can not only be applied in human activity monitoring but also monitoring pressure within microchannels in microfluidic chips, suggesting promising applications in the health and medical fields.

中文翻译：

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基于PDMS/LIG复合薄膜的机电性能可调的三维表面应变传感器

柔性应变传感器在健康监测、智能可穿戴设备和人机交互中发挥着至关重要的作用。应变传感器三维表面评估方法具有更接近实际应变、工作范围更大、更适合多向应变等优点。在这项研究中，开发了一种基于聚二甲基硅氧烷/激光诱导石墨烯（PDMS/LIG）复合薄膜的三维（3D）表面应变传感器。该传感器的机电特性（包括 3D 应变范围和灵敏度）可以通过操纵激光参数和 LIG 图案来调整。获得这些特定特性的关键在于传感器表面裂纹类型和方向的有意设计。值得注意的是，垂直线 (LV) 传感器表现出出色的灵敏度，GF 为 211.3。线平行 (LP) 传感器的 GF 为 115.1。此外，它还具有 25% 的拉伸范围，并在大量的应变/释放测试循环（超过 3000 个循环）中保持稳定的性能。凭借这些优点，3D应变传感器不仅可以应用于人体活动监测，还可以监测微流控芯片中微通道内的压力，在健康和医疗领域具有广阔的应用前景。