Abstract

Disposable microfluidic devices for biological applications

Luc Bousse, Director of Microfluidics, InSilixa Inc

There is a long tradition of seeking synergy between microfabrication technology, most notably silicon device technology, and biology and medicine. As early as the 1970’s, silicon-based ion-sensitive field effect transistors were being studied mainly for biological applications such as blood gas analysis. Today, this device has achieved success as the sensing component of the Ion Torrent NGS system. The recent focus has been on microfluidics consisting of microchannels fabricated in insulating substrates such as glass and polymers. The key appeal is the ability of microfluidic devices to contain a complete analytical system. However, the successful commercialization of microfluidic technology depends on the ability to fabricate cost-effective disposable devices, since reuse is impossible in almost all applications. Combining very high precision and reproducibility with low cost naturally leads to injection molding fabrication technology. An example is BioRad’s digital PCR system that uses a precision molded microfluidic disposable to partition a sample into a large number of stabilized droplets of precisely equal volume, which are then thermally cycled and individually detected. Yet for many applications such as medical diagnostics, the high cost of these microfluidic systems remains an obstacle. InSilixa is addressing that challenge by developing a CMOS Biochip technology to bring MDx to the masses through the marriage of VLSI manufacturing technologies with biotechnology methods. A 2-D biosensor array of individual biosensing elements (“pixels”) consists of miniaturized CMOS-integrated sensors interfaced with capturing molecules (probes) that can interact with bio-molecules of interest. This device thus combines silicon VLSI technology with microfluidics.