DESCRIPTION:
This novel technology can control the properties of shape memory alloys (SMA) and as such represents a fundamentally new asset in micro-actuator design and fabrication. The invention alters transformation temperatures of SMAs such as Ti:Ni by changing the alloy composition. The process deposits two or more SMAs by sputtering one on top of another in a multilayer thin-film stack on Si wafers. The films are subsequently annealed. Each layer in the film stack is of a different alloy composition, with different transformation behavior. As a result, actuation occurs over wider temperature ranges than it would for single films. For some conditions, film actuation is essentially linear with temperature, which has great potential for fabricating MEMS and “Smart Structures” compared to “on-off” actuation typical of SMA actuators. Actuation hysteresis for the composite films made with this technology ranges from 50 C - 60 C to 15 C, depending on the maximum temperature for the cycle.
Application areas include: (1) small, minimally-invasive medical devices, e.g., a gripper device on the end of a catheter, a device to deliver drugs or to take a biopsy, or to snake through the vascular system or to perform brain surgery; and (2) smart structures and MEMS that can take advantage of temperature changes to actuate, with millisecond response times, e.g., to close a switch or dispense fluid or protect hard drives or activate a safety fuse or align lasers for optical communications or cool hot spots on electronics.
STATUS OF DEVELOPMENT:
Proof of principle is completed; the technology can be used to make various thin film prototypes which can be incorporated into devices useful for specific applications
PATENT STATUS:
Intellectual property protection strategy is under review.
RELATIONSHIP SOUGHT:
Commercialization partner to optimize the process, to perform additional research on coating or laminating sheets, ribbons, wires, and multi-alloy materials, and to develop devices under license.
|
