A new optofluidic platform for biological sample processing and optical analysis is made of polydimethylsiloxane (PDMS) and features tunable optics and novel “lightvalves.” (C. Lagattuta)

For well over a decade, electrical engineer Holger Schmidt has been developing devices for optical analysis of samples on integrated chip-based platforms, with applications in areas such as biological sensors, virus detection, and chemical analysis. The latest device from his lab is based on novel technology that combines high-performance microfluidics for sample processing with dynamic optical tuning and switching, all on a low-cost "chip" made of a flexible silicone material.

The new device is made entirely of polydimethylsiloxane (PDMS), a soft, flexible material used in microfluidics as well as in products such as contact lenses and medical devices. The all-in-one device allows for biological sample processing and optical detection on one chip. The chips contain both solid-core and hollow-core waveguides for guiding light signals, as well as fluidic microvalves to control the movement of liquid samples. A special microvalve functions as a “lightvalve,” controlling the flow of both light and fluids.

Potential applications for

this technology include a wide range of biological sensors and analytical devices. For viral diagnostic assays, for example, fluorescently labeled antibodies can be used to tag specific viral strains for optical detection.