An area-variant type MEMS capacitive sensor based on a novel bionic swallow structure for high sensitive nano-indentation measurement. (15th August 2022)

• Record Type: Journal Article
• Authors: Gao, Wendi; Liu, Cunlang; Liu, Tao; Zhao, Libo; Wang, Chenying; Shakoor, Adnan; Luo, Tao; Jing, Weixuan; Yang, Ping; Lin, Qijing; He, Yongqing; Dong, Tao; Jiang, Zhuangde; Sun, Dong
• Is Part Of: Measurement. Volume 200(2022)
• Publication Date: 2022-08-15
• Subjects: MEMS -- Capacitive sensor -- Area-variant -- Bionic -- Nano-indentation; Weights and measures -- Periodicals; Measurement -- Periodicals; Measurement; Weights and measures; Periodicals; 530.8
• DOI: 10.1016/j.measurement.2022.111634
• Languages: English
• ISSNs: 0263-2241

Abstract

Graphical abstract: Highlights: An area-variant type MEMS capacitive force sensor with high sensitivity, resolution, measurement range, and linearity was proposed in this work. A novel bionic swallow structure with multiple differential comb arrays was proposed to achieve a great balance between high sensitivity and compact chip size. A novel differential comb sensing configuration was proposed for eliminating electrostatic interferences and geometry asymmetry resulting from the increasing comb number. The fabricated sensor has been characterized with a robotic microscopy system, its measuring sensitivity was 98.54 aF/nN for a high measurement range of 142 µN with high linearity better than 0.9996. Abstract: In this paper, a high sensitive area-variant type MEMS capacitive sensor was proposed for nano-indentation measurement. The proposed bionic swallow structure processed a high mechanical sensitivity without influences from the load coupling effect. Six comb arrays were optimized and integrated into the proposed sensor with a novel comb sensing configuration for eliminating electrostatic interferences resulting from multiple combs and maintaining compact chip size. Based on the proposed micro-machined process, comb arrays have been fabricated with great consistency, which exhibited a static differential output of 0.0554 pF. The fabricated sensor has been characterized with rigid glass cube and AFM cantilevers, and the measured force sensitivity can reach 98.54 aF/nN for a larger measurement range of 142 µN with a linearity of 0.9996. The fabricated sensor also exhibited a high resolution of 0.9819 nN, indicating its great feasibility in nano-indentation measurement at the sub-nano-Newton level.