Miniaturized chemical/ biomedical processes often require integration of single microfluidic elements such as microvalves and micropumps into complex microfluidic networks for highly parallel processes. As fluidic manipulations in such devices are usually achieved by physical displacement/ deflection of an array of elastic structures using pneumatic or thermal pneumatic actuation, integrated devices require a large number of external equipments such as solenoid valves and electrical modules as well as multiplexing programs to operate, which increases the system cost and complexity. In addition, these peripherals are not amenable to be scaled down with the microfluidic chip. As such, a microfluidic platform with simple actuation and multiplexing mechanism would be desirable for microfluidic integration.
Researchers at the University of Michigan have developed an optically addressed actuator array with latched operation. The microactuator array consists of individual phase change-based actuators addressed by localized heating through focused light patterns, which can be provided by a modified projector or high power laser pointer. A common pressure manifold for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light “writing” during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs.
Applications and Advantages
- Actuation in microfluidics systems
- Simplified, compact system
- Reconfigurable, energy-efficient, and low cost-nl-multiplexing solution for microfluidic-nl-applications