Self-Latching Piezocomposite Actuator

Energy management is one of the most challenging issues in the world today. Accordingly, various energy harvesting technologies have gained attention, including harvesting energy from ambient vibration sources using piezoelectric materials. However, conventional piezoelectric energy harvesting transducer (PEHT) structures have effective piezoelectric constants that are lower than about 10^4 pC/N, (resonant mode). These low piezoelectric constants lead to conventional PEHTs not being able to harvest electric power effectively. Further, for a specific vibration/motion source, it would be advantageous to maximize the mechanical energy captured from the vibration structure into the piezoelectric device and to convert a greater fraction of that mechanical energy into electrical energy more efficiently. This invention is a system and method using multistage force amplification of piezoelectric energy harvesting transducers (MFAPEHTs) to increase the effective piezoelectric constant to >10^6 pC/N and to increase the mechanical energy input to the device. The invention utilizes 33 mode PZT to permit maximum coupling between the input mechanical energy with the piezoelectric material, and multilayer construction of single crystal PMN-PT material to significantly amplify the voltage/charge generation and storage from the applied mechanical force.

Highly distributed next-generation computer-based systems require self-managing environments that feature a range of autonomic computing techniques. This functionality is provided by collaborating agents, and includes an apoptotic (self-destruct) mechanism, autonomic quiescence (self-sleep), and others. The apoptotic feature is necessary to maintain system security and integrity when a component endangers the overall operation and viability of the entire system. However, the self-destruction of an agent/component may remove a key piece of functionality. The novel autopoietic functionality provides the capability to duplicate or substitute a new agent that provides the functionality of the self-destructed component.

The SMART solar sail includes a reflective film stretched among nodes of a SMART space frame made partly of nanotubule struts. A microelectromechanical system (MEMS) at each vertex of the frame spools and unspools nanotubule struts between itself and neighboring nodes to vary the shape of the frame. The MEMSs is linked, either wirelessly or by thin wires within the struts, to an evolvable neural software system (ENSS) that controls the MEMSs to reconfigure the sail as needed. The solar sail is highly deformable from an initially highly compressed configuration, yet also capable of enabling very fine maneuvering of the spacecraft by means of small sail-surface deformations. The SMART Solar Sail is connected to the main body of the spacecraft by a SMART multi-tether structure, which includes MEMS actuators like those of the frame plus tethers in the form of longer versions of the struts in the frame.

Rudders have long served as the primary flight control surface as is pertains to aircraft yaw. Breaking this mold, NASA's SAW technology is a game-changing development in aircraft wing engineering that reduces rudder motion required to control aircraft. The benefits of reduced rudder dependency led NASA to develop the outer aileron yaw damper to further decrease or eliminate rudder dependency for aircraft using SAWs. As mentioned, SAWs use shape memory alloy actuators to articulate the outer portion of the wing, effectively creating a movable wingtip. NASA's invention uses an outer aileron located on the wingtips, which is driven (along with the inner ailerons) by a novel control algorithm. The control algorithm, taking into account the wingtip positions, manipulates the outer ailerons to achieve the desired yaw rate. At the same time, it positions the inner ailerons to counter roll rate resulting from the outer aileron. In other words, the control algorithm calculates a control surface ratio (i.e., position of inboard aileron and outboard aileron) that produces desired yaw and roll accelerations. The system can also be used to offset the existing rudder in current or future aircraft designs. A second part of NASAs novel outer aileron control algorithm modifies the aircrafts rudder loop gain in proportion to outer aileron usage. This allows the outer ailerons and rudder to work in tandem, while at the same time reducing rudder usage. As a result of this NASA invention, required rudder usage can be reduced or eliminated for aircraft with SAWs. Consequently, the size of rudders and vertical tail structures can be reduced, which in turn reduces weight and parasitic drag. The result is an aircraft with increased performance and fuel efficiency.

On occasion, anomalies may appear in the highly dynamic test data obtained during rocket engine tests, which are investigated and corrective action may be mandated before subsequent testing. Also, it is often unclear if anomalies in recorded signals are due to differences between the Low and High Speed Data Acquisitions Systems, difference between the transducers, a failed transducer, or if everything is working correctly and the system were actually accurately recording real events. Commercial test equipment suitable for testing piezoelectric sensors is expensive and requires that the sensor be removed from the test article for evaluation. With the monitoring system developed, degraded sensor performance can be quickly and economically identified. This system can evaluate installed piezoelectric sensors, without requiring physical contact with or removing them from their mounted locations. Tests are conducted through cabling. Since it is not necessary to remove the device, data that reflect the devices specific physical configuration (such as as-mounted resonant frequency) are retained, and devices that are physically inaccessible can still be tested. The testing system is not limited to identifying degraded performance in the sensors piezoelectric elements; it can detect changes within the entire sensor, and sensor housing. The system can be made portable, in a battery powered sealed box, for testing in the field. Since physical contact with the sensor is not necessary, therefore, monitoring can be done as far away as 250 feet, or longer if certain provisions are made.