The Hydrogel Valve – Properties and Function
To add liquid, to start and stop reactions, a dead volume free microvalve (GeSiM patent) can be placed into the flow system.
The valve is made from a silicon chip but comes with different housings for convenient handling. Most popular version is called “HG-7″, based on a PEEK-housing with 1/16” fitting.
The valve chip incorporates a small but well defined amount of a hydrogel immobilized in a liquid transparent chamber. The surrounding heater controls the temperature of the chamber in a limited range around the swelling temperature of the hydrogel.
For operation of the valve nothing but 250 mW power is required. The Fluid Processor provides full control of the device.
The sample liquid gets in contact with the enclosed hydrogel. Therefore the valve is mainly made for aqueous solutions but tolerates <15 % methanol, acetone.