A temperature control system integrated with a microfluidic chip for sperm analysis

Microfluidic technology has found many applications; yet, the extension of this technology into the area of sperm health evaluation has been limited. For this application, the need to maintain the microenvironment at a temperature conducive for gamete activity is of crucial importance. Although some existing commercial microscopes are currently equipped with incubators, they are relatively expensive, lack flexibility and convenience for microfluidic operations. Here we report the sperm analysis on a microfluidic chip using a custom-made temperature control system. The system consists of a water chamber with a window at the bottom, a Pt100 temperature sensor, a temperature control module, a set of Peltier elements, and a DC power supply. A Polydimethylsiloxane (PDMS) microfluidic chip was packaged and immersed in the water chamber, with sperm loaded into the chip through a silicone tube using a syringe. The results of sperm motility were then evaluated via microscopic observation. This temperature control system is cost-effective, portable, and compatible with different kinds of inverted optical microscopes. Experiments also demonstrate that the system can provide the stable, accurate and uniform temperature environment necessary for microfluidic sperm analysis. ? 2009 SPIE.EI