As the consumer demand for smaller, more sophisticated computers grows, the need arises for new air cooling methods that will work in geometries that mechanical fans cannot. Ionic winds (also known as electrohydrodynamic flows) are flows that are produced by the generation of a gas discharge. These flows do not require moving parts to operate, making them attractive for small form-factor device...

Recently, piezoelectric and triboelectric energy harvesting devices have been developed to convert mechanical energy into electrical energy. Especially, it is well known that triboelectric nanogenerators have a simple structure and a high output voltage. However, whereas nanostructures improve the output of triboelectric generators, its fabrication process is still complicated and unfavorable i...

This paper presents a computational method for detecting vibrations related to eccentricity in ultra precision rotation devices used for nano-scale manufacturing. The vibration is indirectly measured via a frequency domain analysis of the signal from a piezoelectric sensor attached to the stationary component of the rotating device. The algorithm searches for particular harmonic sequences assoc...

A new touch sensor device has been demonstrated with molybdenum disulfide (MoS2) field effect transistors stacked with a piezoelectric polymer, polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE). The performance of two device stack structures, metal/PVDF-TrFE/MoS2 (MPM) and metal/PVDF-TrFE/Al2O3/MoS2 (MPAM), were compared as a function of the thickness of PVDF-TrFE and Al2O3. The sensitivity...

A wireless, in-situ ultrasonic guided wave structural health monitoring (SHM) system has been developed and tested for aircraft wing inspection. It applies small, low cost and light weight piezoelectric (PZT) disc transducer network to the structural surface, and embeds a miniaturized diagnostic device for data collection and analysis. The whole system can be powered by an energy harvesting dev...

The mechanism which real flying insects use to detect body rotation has been simulated. The results show that an angular rate sensor can be made based on such a biological mechanism. Two types of biomimetic gyroscopes have been constructed using foils of stainless steel. The first device is connected directly to a compliant cantilever. The second device is placed on a mechanically amplifying fo...

1. Abstract There are several optical applications in which a mirror or lens requires accurate manipulation, for example in microscanning or focusing optical systems. Typically, such devices are designed on a trial-and-error basis. To improve on this procedure, we apply topology optimization in the design of a piezoelectric micropositioner. The mechanism employs two piezoelectric stack actuator...

The purpose of this thesis is to investigate piezoelectric and ferroelectric thin film device technologies for application in microwave oscillators. Thin film varactors based on ferroelectric materials are considered. Experimental development of practical varactors based on paraelectric phase BaxSr1−xTiO3, in terms of layout design and model extraction, is presented in the thesis. Experimental ...

We demonstrate the operation of a device that can produce chitosan nanoparticles in a tunable size range from 50-300 nm with small size dispersion. A piezoelectric oscillator operated at megahertz frequencies is used to aerosolize a solution containing dissolved chitosan. The solvent is then evaporated from the aerosolized droplets in a heat pipe, leaving monodisperse nanoparticles to be collec...

This paper presents experimental observations and a theoretical analysis of the operation of drop-on-demand piezoelectric ink jet devices. By studying experimentally the dependence of several operating characteristics on the length of the cavity in the nozzle of an ink jet device, we have gained insight into the physical phenomena underlying the operation of such a device. It is concluded that ...