Patent ID: 7625474

Claim:
A method for providing a microfluidic system weaklink valve, comprising the steps of: a.) providing an electrokinetic (EK) pump comprising a porous medium disposed within the EK pump and covalently bonded to an interior surface; b.) filling the EK pump with a buffer fluid capable of electroosmotic flow; c.) connecting a first end of the EK pump to a fluid reservoir containing a quantity of a polymerizable solution comprising monomers of N,N-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl)-ammonium betaine (SPE); d.) connecting a second end of the EK pump to a closed fluidic system; e.) displacing a portion of the buffer fluid within the porous medium with a portion of the solution of SPE monomers; f.) applying an electrical potential between the first and second ends sufficient to provide an electroosmotic transport into the closed fluidic system thereby hydraulically pressurizing the EK pump and the closed fluidic system; g.) polymerizing the portion of the solution of SPE monomers to form a pressure seal, wherein the hydraulic pressure within the closed fluidic system is maintained even if or when the electrical potential is subsequently compromised, removed or lost.