Several new projects have been derived by making bridges with the field of MEMS – Micro Electro-Mechanical Systems. MEMS use techniques from semiconductor computer chip manufacturing to create new devices. For example, Dr. Chiao of Mechanical Engineering is leading a project to design a new implantable device to treat disease. Our specialty, ultrasound, plays a role in this project through sonoporation. We are designing a millimetre-sized device that incorporates a drug reservoir, ultrasound transducer and electronics. Our initial work on cultured prostate cancer cells showed that high intensity ultrasound can produce cavitation, which results in microbubbles that expand and collapse leaving behind small holes in nearby cell walls. This technique, called sonoporation, was shown to improve the ability to deliver anti-cancer drugs to the cells. New drugs continue to be developed to combat cancer, but the delivery of drugs through the cell wall has traditionally been a critical stumbling block. We are continuing this early work to develop the miniature devices that combine controlled release of a drug with sonoporation at appropriate times to improve drug uptake. If successful, the device will provide a new way to treat cancer that has fewer side effects than current cancer therapy. This work is supported by an NSERC Strategic grant awarded in 2007.
In another project that combines ultrasound with MEMS, we are working on a project led by Prof. Cretu to design a new type of ultrasound transducer. Traditional ultrasound transducers use small fragile piezoelectric crystals to convert electrical energy into sound energy. Replacing the piezoelectric crystals with specialized MEMS devices has the ability to improve the quality of ultrasound signals. MEMS technology also has the potential to radically decrease the cost of the transducer by leveraging the cost-efficiencies of computer chip mass-manufacturing. Finally, MEMS also opens up new opportunities for custom transducer configurations that are not possible with traditional piezoelectric crystals. This work is supported by another NSERC Strategic grant awarded in 2008.