Design and fabrication of a novel microswitch made in LTCC-PDMS technology applicable to micro total analysis systems

Abstract

The physical design and implementation of an LTCC on–off microswitch device is demonstrated. One model was used to describe microchannel fluidic behavior, especially those with rectangular cross-section, routinely used in microfluidic devices. Another model to describe PDMS microbridge deformation was applied, allowing for estimating the elastic stiffness of several manufactured membranes. From this approach, microswitch design was conducted regarding the simulation results associated with both models, aiming at miniaturization. Applying LTCC-PDMS fabrication methodology, the fluidic devices were manufactured as established by theoretical design and an experimental setup was proposed in order to evaluate system performance. Experimental investigations indicate that a weight of 120 g was necessary to reduce the water flow rate of the normally open LTCC-PDMS microswitch from 0.42 mL/min to 50 μL/min when submitted to a controllable pressure-driven system. The leakage observed when testing the fabricated microswitches regards the rough way in which the PDMS membrane was attached to the LTCC body. However, experimental results suggest that the novel microswitch can operate satisfactorily regarding micro total analysis applications.