Topic : MEMS Devices with Polymer based Materials

楊燿州 主任
國研院儀科中心 主任

2019/10/17 (Thu) 3:30 pm - 5:20 pm
Engineering 5 Building B1 International Conference Hall (工程五館 B1 國際會議廳)

This talk presents three microdevices realized by using soft materials: an ultra-sensitive temperature sensor for non-contact real-time respiratory monitoring, a microgripper that can be wirelessly manipulated using magnetic fields, and a tactile sensor array that employs the tunneling piezoresistive effect for achieving high sensitivity.
The real-time respiratory monitoring device employs a sensing element with acrylate-based material with a positive temperature coefficient (PTC). The acrylate-based material exhibits an order-of-magnitude variation in resistivity over a temperature change of a few degrees, and is capable of detecting tiny temperature changes induced by exhalation air flow. The transient behaviors of the fabricated device were measured. The fabricated device possesses the advantages such as low cost, energy efficient, and simple operation compared to common existing methods.
The proposed microgripper can move freely in liquids when driven by direct current (dc) magnetic fields, and perform a gripping motion by using alternating current (ac) magnetic fields. The gripper is fabricated from a biocompatible hydrogel material that can be employed for intravascular applications. The actuation mechanism for gripping motions is realized by controlling the exposure dose on the hydrogel composite during the lithography process. The preliminary characterization of the device is also presented. The measurement results show that the gripping motion reached a full stroke at approximately 38 ºC.
The proposed highly-sensitive tactile sensor is made by dispersing multi-wall carbon nanotubes into polydimethylsiloxane (MWCNT and PDMS) polymer patterned with microdome structures using nylon membrane filter substrate. The fabricated sensing device features advantages such as ultra-high sensitivity, flexibility, and simple fabrication process. The tunneling piezoresistive effects of the interlocked microdome structures with different MWCNT concentrations are demonstrated. The resistance change of the sensor array due to different types of motions was measured.