Replication of three-dimensional valves from printed wax molds

We describe microfluidic vias, channels and valves fabricated by replication molding of polydimethylsilicone (PDMS) into printed wax molds. Additionally we show how completely polymer embedded microfluidic circuits can be realized with this technique. A novel three-dimensional microfluidic valve is also demonstrated which is robust against swelling and which operates at up to 30 psi flow pressure. This method for defining microfluidic devices offers higher pressure tolerance and more resistance to corrosive solvents, as de-lamination problems can be avoided. It also enables a great flexibility in choice of replicated polymers and three-dimensional interconnection topologies to form complex microfluidic circuits for microbiochemical analysis.