Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072, China.
ACS Appl Mater Interfaces. 2020 Dec 9;12(49):55362-55371. doi: 10.1021/acsami.0c14314. Epub 2020 Nov 24.
High sensitivity and linear response over a wide sensing range are important in flexible pressure sensors for their practical applications in biomimetic electronics and human-machine interactions. Previous studies regarding flexible pressure sensors have primarily focused on their high sensitivity, whereas they generally exhibit a narrow linear sensing range. In this article, a hierarchical structure with conical secondary features is reported, and its role in enhancing the linear sensing range of piezoresistive pressure sensors is demonstrated. We find that the conical secondary features on the hierarchical structure significantly improve the linear relationship between the contact area and applied force over a broad range. This advantage endows the sensor with a wide linear sensing range. To obtain this type of hierarchical structure, pollen grains of wild chrysanthemum are exploited as templates, and the prepared sensor presents a high sensitivity of 3.5 kPa over an ultrawide response range of 0-218 kPa with good linearity via a coefficient of determination () of 0.997. Furthermore, owing to the simple and scalable process, a sensor array with high density is fabricated to map the spatial pressure distribution and simulate an electronic skin to detect Braille characteristics.
在生物电子学和人机交互等实际应用中，对于柔性压力传感器而言，高灵敏度和较宽的传感范围的线性响应非常重要。之前关于柔性压力传感器的研究主要集中在其高灵敏度上，而它们通常表现出较窄的线性传感范围。本文报道了一种具有锥形二次特征的分层结构，并证明了其在提高压阻式压力传感器线性传感范围方面的作用。我们发现，分层结构上的锥形二次特征显著改善了在较宽范围内接触面积与所受外力之间的线性关系。这一优势赋予了传感器较宽的线性传感范围。为了获得这种类型的分层结构，我们利用野菊花花粉作为模板，所制备的传感器在超宽的响应范围（0-218 kPa）内具有 3.5 kPa 的高灵敏度，通过决定系数（R²）达到 0.997，具有良好的线性度。此外，由于该工艺简单且具有可扩展性，我们制造了一个具有高密度的传感器阵列，以绘制空间压力分布并模拟电子皮肤来检测盲文特征。
