Nagatomo Tatsuho, Miki Norihisa
School of Integrated Design Engineering, Keio University, Yokohama 223-8522, Japan.
Department of Mechanical Engineering, Keio University, Yokohama 223-8522, Japan.
Micromachines (Basel). 2018 Nov 3;9(11):570. doi: 10.3390/mi9110570.
Polymer-based flexible micro electro mechanical systems (MEMS) tactile sensors have been widely studied for a variety of applications, such as medical and robot fields. The small size and flexibility are of great advantage in terms of accurate measurement and safety. Polydimethylsiloxane (PDMS) is often used as the flexible structural material. However, the sensors are likely subject to large parasitic capacitance noise. The smaller dielectric constant leads to smaller influences of parasitic capacitance and a larger signal-to-noise ratio. In this study, the sensor underwent ultraviolet (UV) exposure, which changes Si⁻CH₃ bonds in PDMS to Si⁻O, makes PDMS nanoporous, and leads to a low dielectric constant. In addition, we achieved further reduction of the dielectric constant of PDMS by washing it with an ethanol⁻toluene buffer solution after UV exposure. This simple but effective method can be readily applicable to improve the signal-to-noise ratio of PDMS-based flexible capacitive sensors. In this study, we propose reduction techniques for the dielectric constant of PDMS and applications for flexible capacitive force sensors.
基于聚合物的柔性微机电系统（MEMS）触觉传感器已被广泛研究用于各种应用，如医疗和机器人领域。其小尺寸和灵活性在精确测量和安全性方面具有很大优势。聚二甲基硅氧烷（PDMS）常被用作柔性结构材料。然而，这些传感器可能会受到较大的寄生电容噪声影响。较小的介电常数会导致寄生电容的影响较小，信噪比更大。在本研究中，传感器经过紫外线（UV）照射，这会将PDMS中的Si⁻CH₃键转变为Si⁻O，使PDMS形成纳米多孔结构，并导致介电常数降低。此外，我们在UV照射后用乙醇⁻甲苯缓冲溶液洗涤PDMS，实现了其介电常数的进一步降低。这种简单但有效的方法可很容易地应用于提高基于PDMS的柔性电容式传感器的信噪比。在本研究中，我们提出了降低PDMS介电常数的技术以及柔性电容式力传感器的应用。
