모바일 메뉴 닫기
 
Title
[BK21 seminar] 3rd Dec(Fri) Prof. Jungchul Lee(KAIST) "Beyond mass sensing with microchannel resonators“
Date
2021.12.03
Writer
기계공학부
게시글 내용

Please give a lot of attention and participation from the members of the Mechanical Engineering department.



Title : Beyond mass sensing with microchannel resonators

Speaker: Prof. Jungchul Lee

Affiliation: KAIST

Date: 2021. 12. 3.(Fri) 16:00

Venue: Engineering Building D403

Host: Prof. Jongbaeg Kim

Abstract

Microchannel cantilevers, one of promising physical microelectromechanical systems (MEMS) devices that have embedded microchannels, have been widely used in gravimetric sensing applications of liquids and particles introduced into the channel or dispensing/patterning applications with liquid phase materials when a dispensing nozzle is additionally configured near their free ends. Although there are numerous potential applications at elevated temperatures such as material synthesis, calorimetric measurements, and phase change mediated manipulation or control, to name a few, microchannel cantilevers are mostly used at or near room temperature mainly due to the absence of integrated active heating elements. Towards various applications under fast and quantitative temperature modulation, we have developed fluidic resonators with integrated heating capability. First, a stainless steel tube resonator was made by simply clamping a straight stainless steel tube on CNC-machined jigs along with piezoelectric chips. The stainless-steel tube resonator under Joule heating was successfully employed for boiling point measurements of water. After the proof-of-concept study with the stainless-steel tube resonator, we have switched to microfabricated channel resonators with an integrated heater for sensitivity enhancement. Heater-integrated microchannel cantilevers with or without a dispensing nozzle were batch-fabricated via sacrificial process, ion implantation, and other typical microfabrication processes. Fabricated heater-integrated microchannel cantilevers were thoroughly calibrated and characterized in a variety of coupled physical domains. Upon pulsed operations, electrothermomechanical time constants extracted from the transient resonance frequency provided a new measurement modality for thermophysical properties of the fluid contained in the microchannel. When a glycerol-water binary mixture was pulsed heated above its boiling point, atomized droplets could be spray-ejected out of the integrated nozzle.


Attachments
20211203_BK21_이정철 교수(김종백 교수님).png