self-contained fully-enclosed microfluidic cartridge for lab on a chip

• Published in: Biomedical microdevices 2009-12, Vol.11 (6), p.1279-1288
• Main Authors: Yobas, Levent, Feng Cheow, Lih, Tang, Kum-Cheong, Yong, Shien-Eit, Kye-Zheng Ong, Eleana, Wong, Lionel, Cheng-Yong Teo, William, Ji, Hongmiao, Rafeah, Siti, Yu, Chen
• Format: Article
• Language: English
• Subjects: Biological and Medical Physics; Biomedical Engineering and Bioengineering; Biophysics; DNA - isolation & purification; Engineering; Engineering Fluid Dynamics; Fluid dynamics; Integrated circuits; Microfluidic Analytical Techniques - instrumentation; Nanotechnology; Polymerase Chain Reaction
• ISSN: 1387-2176; 1572-8781
• DOI: 10.1007/s10544-009-9347-z

We describe a self-contained fully-enclosed cartridge for lab-on-a-chip applications where sample and reagents can be applied sequentially as is performed in a heterogeneous immunoassay, or nucleic acid extraction. Both the self-contained and fully-enclosed features of the cartridge are sought to ensure its safe use in the field by unskilled staff. Simplicity in cartridge design and operation is obtained via adopting a valveless concept whereby reagents are stored and used in the form of liquid plugs isolated by air spacers around a fluidic loop. Functional components integrated in the loop include a microfluidic chip specific to the target application, a novel peristaltic pump to displace the liquid plugs, and a pair of removable tubing segments where one is used to introduce biological sample and while the other is to collect eluant. The novel pump is fabricated through soft-lithography technique and works by pinching a planar channel under stainless-steel ball bearings that have been magnetically loaded. The utility of the cartridge is demonstrated for automated extraction and purification of nucleic acids (DNA) from a cell lysate on a battery-operated portable system. The cartridge shown here can be further extended to sample-in-answer-out diagnostic tests.