On-chip microfabrication of thermally controllable PNIPAAm microvalves by using optical maskless stereolithography

• Published in: Sensors and actuators. A. Physical. Vol. 247; pp. 397 - 402
• Main Authors: Huang, Bo-bo, Yin, Ming-jie, Zhang, A. Ping, Ye, Xue-song
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-08-2016
• Subjects: Microfabrication; Microfluidics; Microvalves; PNIPAAm; Microvalves; Microfabrication; PNIPAAm; Microfluidics
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2016.06.019

•It is the first report to optically pattern PNIPAAm into complex 3D microstructures by using optical maskless lithography technology.•An adaptive in-situ optical microfabrication process is demenstrated to fabricate PNIPAAm microvalves in a microfluidic chip.•The fabricated PNIPAAm microvalve can be repeatedly switched off and on by tuning its tempeatrue between 20 and 37°C, respectively.•The proposed optical microfabrication approach is promising to advance microfluidics chip towards large-scale on-chip device integration.
A growing trend of lab-on-a-chip (LOC) technologies is to achieve large-scale integration of components and functionalities. In this paper, we present an optical in-situ microfabrication technology, i.e. optical maskless stereolithography, for on-chip component fabrication and integration. It is demonstrated that poly(N-isopropylacrylamide) (PNIPAAm) can be rapidly patterned into high-resolution 2D/3D microstructures and in-channel PNIPAAm microvalves can be adaptively fabricated on a microfluidic chip by using the UV light based optical maskless exposure technology. The PNIPAAm microvalve can be repeatedly switched off and on by tuning its temperature between 20 and 37°C, respectively. Such an in-situ microfabrication approach is promising in the development of multifunctional microfluidic chips integrated with micro-sensors and actuators.