The EU microbuilder project has developed a one-stop shop to support companies, especially SMEs, in the rapid design and manufacture of novel micro-devices for use in applications ranging from medical diagnosis to mobile phones.
They have created a set of tools that should reduce the time it takes to get from a good idea for a micro-device to a commercial, sellable product.
The microBUILDER services are focused on microfluidic devices like:
■Valves and pumps
■Sensors for instrumentation
■Gas and flow sensors
One of the hardest obstacles for developing novel devices is finding ways to integrate different materials into a single device. For example, a blood sample may first flow through channels in a polymer slide and react with a labelled antibody. But the detection of the target molecule may involve a silicon-based sensor. You therefore need to continue the channel through silicon, without any perturbation to the flow.
“A lot of sensors are based on silicon, but silicon is much more expensive than polymer,” explains Furuberg. “To keep micro-devices as cheap as possible you want to minimise the amount of silicon. So you need to find ways to plug different modules made of different materials together.”
Starting with a commercial micro-fluidics polymer prototyping kit (from ThinXXS), the project successfully developed a ‘template’ polymer system into which silicon components can be simply ‘plugged in’.
The partners also developed standard procedures for designing and manufacturing other devices made from several materials, including silicon and glass, and fluid channels coated with reactive molecules.
The partners had particular success in the integration of a material known as piezoelectric thin film (PZT) into micro-structures. PZT bends when a voltage is put across it; it also produces a voltage when it is bent or distorted. PZT is ideal for microscopic valves, switches and sensors. A follow-up research project, PiezoVolume, funded under the Seventh Framework Programme (FP7, NMP) for research, is seeking to automate this PZT thin film manufacturing process.
The integration of different materials and the application of PZT are just two examples of a diverse portfolio of advances made by the project. The partners produced several prototype devices to demonstrate the project’s achievements, including a cell counter, a gas detector, a DNA extractor and a flow sensor. The PZT technology has already been used by a Norwegian firm to build a tiny auto-focusing lens for small CCD cameras.