Tan Edward K W, Rughoobur Girish, Rubio-Lara Juan, Tiwale Nikhil, Xiao Zhuocong, Davidson Colin A B, Lowe Christopher R, Occhipinti Luigi G
Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK.
Microsystems Technology Laboratories, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Sci Rep. 2018 Apr 26;8(1):6607. doi: 10.1038/s41598-018-24901-2.
Existing techniques for patterning metallic structures on elastomers are limited in terms of resolution, yield and scalability. The primary constraint is the incompatibility of their physical properties with conventional cleanroom techniques. We demonstrate a reliable fabrication strategy to transfer high resolution metallic structures of <500 nm in dimension on elastomers. The proposed method consists of producing a metallic pattern using conventional lithographic techniques on silicon coated with a thin sacrificial aluminium layer. Subsequent wet etching of the sacrificial layer releases the elastomer with the embedded metallic pattern. Using this method, a nano-resistor with minimum feature size of 400 nm is fabricated on polydimethylsiloxane (PDMS) and applied in gas sensing. Adsorption of solvents in the PDMS causes swelling and increases the device resistance, which therefore enables the detection of volatile organic compounds (VOCs). Sensitivity to chloroform and toluene vapor with a rapid response (30 s) and recovery (200 s) is demonstrated using this PDMS nano-resistor at room temperature.
目前在弹性体上制作金属结构的技术在分辨率、成品率和可扩展性方面存在局限性。主要限制在于其物理性质与传统洁净室技术不兼容。我们展示了一种可靠的制造策略，可在弹性体上转移尺寸小于500纳米的高分辨率金属结构。所提出的方法包括在涂有薄牺牲铝层的硅上使用传统光刻技术制作金属图案。随后对牺牲层进行湿法蚀刻，从而释放出带有嵌入式金属图案的弹性体。使用这种方法，在聚二甲基硅氧烷（PDMS）上制作了最小特征尺寸为400纳米的纳米电阻器，并将其应用于气体传感。PDMS中溶剂的吸附会导致膨胀并增加器件电阻，因此能够检测挥发性有机化合物（VOCs）。在室温下使用这种PDMS纳米电阻器展示了对氯仿和甲苯蒸气的灵敏度，响应迅速（约30秒）且恢复迅速（约200秒）。
