2006 Award Winner
Government Award Winner
MacroFiber Composite Actuator and Sensor (MFC)
Lead NASA Center:
Langley Research Center (LaRC)
The MacroFiber Composite Actuator and Sensor (MFC) is an embodiment of a new type of piezoelectric device. When voltage is applied to a piezoelectric device, an electric field is generated parallel to the piezoelectric fibers. This electric field produces a uniform mechanical strain proportional to the applied electric field up to a saturation point. Conversely, when the device is mechanically strained, a voltage is produced in response to the magnitude and direction of the applied load. The MFC technology is a complete make over and refinement of earlier methods to enable the fabrication of piezoelectric actuators and sensors with increased performance, reliability and manufacturability at reduced cost. For instance, rather than use expensive round piezoelectric fibers, the MFC uses commercial piezoelectric wafers that are diced into square fibers and placed, pre-aligned, directly onto commercially produced polyimide copper films. There is no direct handling of the piezo-material, no health issues with lead oxides and no fiber breakage.
Above: The MacroFiber Composite Actuator and Sensor, embodiment of a new type of piezoelectric device
Additionally, the concepts used to make the MFC allows for the robust assembly of most any commercial dielectric ìsmartî materials to be assembled into a low cost, durable, flexible, sealed package for use as both an actuator and sensor in a variety of shapes and sizes. When compared to standard piezoelectric systems, the MFC is much more durable and provides increased unidirectional control. Furthermore, the MFC is designed to be readily integrated into a system as an add-on component or integrated during manufacture. The MFCís flat profile and use as a sensor and an actuator allows for use in critical or tight areas where other technologies with larger volumetric profiles cannot be used. This technology, in combination with the ability to self power wireless circuitry from the electricity generated from flexing the MFC, enables additional health monitoring application on complex rotating components, such as turbomachinery, or in remote areas, such as hazardous environments, where additional wiring and power sources can be extremely difficult to implement.
MFC has been used experimentally on a number of NASA missions to prove concepts, including mitigation of buffeting of vertical stabilizers on aircraft, solar sails and inflatable space structures, morphing systems, structural health monitoring devices, vibration damping and noise cancellation strategies, structural shaping and stiffness control, aeroelelastic instability mitigation, and dozens of other active control solutions. It has also found commercial appplications in similar areas, most notably for reduction of vibration in automotive drive shafts for Volkswagen.