Paraffin Actuators in Microfluidic Systems

There is a need for reliable valves and pumps in microfluidics. A good microactuator is the key for low cost and high performance of these components. Paraffin wax is a promising material to be used as actuator material as is can produce large forces and large strokes. Further, the material is inexpensive and, none the less, the thermal heating of the material can be made with low voltages. All these properties are of interest in flow control components in microfluidics, and especially for disposables and in potable systems. In this work, paraffin wax has been used in devices and concepts. A valve for high-pressures, a peristaltic pump, a multi-stable actuator, and injector has been shown. A material study was performed on binary mixtures of pure paraffin (n-alkanes), and a concept for loading fluid into a sealed reservoir was shown as well. Several injectors were demonstrated in a Lab-on-a-chip system with other microfluidic components. High pressure applications in microfluidics along with the multi-stable actuator show good potential. However, the drive and control has to be further developed.