Sensors and Actuators A 123–124 (2005) 453–458 Fabrication of a peristaltic PDMS micropump Ok Chan Jeong a , Sin Wook Park b , Sang Sik Yang b, ∗ , James Jungho Pak c a Center for Promotion of the COE Program, Ritsumeikan University, Japan b Division of Electrical and Computer Engineering, Ajou University, San 5 Wonchun-Dong, Yeongtong-Gu, Suwon 443-749, Republic of Korea c Department of Electrical Engineering, Korea University, Republic of Korea Received 23 September 2004; received in revised form 16 December 2004; accepted 9 January 2005 Available online 23 February 2005 Abstract This paper presents fabrication and drive test of a peristaltic PDMS micropump actuated by the thermopneumatic force. The micropump consists of the three peristaltic-type actuator chambers with microheaters on the glass substrate and a microchannel connecting the chambers and the inlet/outlet port. The micropump is fabricated by the spin-coating process, the two-step curing process, the molding process using negative photoresist, etc. The diameter and the thickness of the actuator diaphragm are 2.5 mm and 30 m, respectively. The meniscus motion in the capillary tube is observed with a video camera and the flow rate of the micropump is calculated through the frame analysis of the recorded video data. The maximum flow rate of the micropump is about 0.36 L/s at 2 Hz for the zero hydraulic pressure difference, when the three-phase input voltage is 20V. © 2005 Elsevier B.V. All rights reserved. Keywords: Peristaltic thermopneumatic micropump; Polydimethylsiloxane (PDMS); Flow rate 1. Introduction Recently, various microfluidic devices with no mechanical moving part have been fabricated with polydimethylsiloxane (PDMS) for applications in bio-chip and lab-on-a-chip because of its key merits, such as a transparency, a bio- compatibility and a low production cost [1,2]. However, a study on the micropump with a mechanical actuator fabricated by using multi-stacked PDMS-molding technique has not been reported even though the PDMS elastomer has some advantages like the remarkable flexibility and the simple fabrication process including the reliable bond- ing process between PDMS-to-PDMS or PDMS-to-glass [3]. In Ref. [4], the membrane-type micropumps with vari- ous actuators are well described. The advantages and dis- advantages of each micropump are also discussed from the viewpoint of the power consumption, the integration method, ∗ Corresponding author. Tel.: +82 331 219 2481; fax: +82 331 212 9531. E-mail address: ssyang@ajou.ac.kr (S.S. Yang). the response time, the operation frequency and voltage, the fabrication process, the actuation efficiency, etc. For the simple fabrication process and the large volume stroke of the micropump, the thermopneumatic actuation method is suggested. The micropump requires a microvalve unit for the one-way flow rate of the working fluid. Microvalves are classified into the passive and active valves [5,6]. The active valve is useful to control the flow rate under the some pressure difference, but its fabrication process is complicated. The passive check valve opens only to the forward pressure and have simple structures compared to the active valve. However, with the passive check valve, the control of reverse flow rate under the pressure difference is impossible. In this paper, as new approach to the fabrication of a membrane-type micropump and its associated components, the peristaltic micropump using the thermopneumatic actua- tion has been fabricated. The peristaltic-type actuators can be operated as the dynamic valves and controlled easily by the applied electric input power without any additional process for the fabrication of the microvalves unit. 0924-4247/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.sna.2005.01.035