INTRODUCTION: Micro Electro Mechanical Systems (MEMS) are fabricated with an in-plane fabrication technology. Out-of-plane structures can be designed to be assembled to provide thermal and electrical isolation from the substrate [1 -3]. These isolations can potentially improve the performance of a range of MEMS devices by decreasing any unwanted coupling effects or parasitic losses from the dev...

This study demonstrates a method for harvesting the electrical power by the piezoelectric actuator from vibration energy. This paper presents the energy harvesting technique using the piezoelectric element of a bimorph type driven by a geared motor and a vibrator. The geared motor is a type of PWM controlled device that is a combination of an oval shape cam with five gears and a speed controlle...

Piezoelectric bimorphs have been used as a micro-gripper in many applications, but the system might be complex and the response performance might not have been fully characterized. In this study the dynamic characteristics of bending piezoelectric bimorphs actuators were theoretically and experimentally investigated for micro-gripping applications in terms of deflection along the length, transi...

The abrupt first-order metal-insulator phase transition in single-crystal vanadium dioxide nanowires (NWs) is engineered to be a gradual transition by axially grading the doping level of tungsten. We also demonstrate the potential of these NWs for thermal sensing and actuation applications. At room temperature, the graded-doped NWs show metal phase on the tips and insulator phase near the cente...

Fluid transport is accomplished in a micro throttle pump (MTP) by alternating deformation of a micro channel cast into a PDMS elastomeric substrate. The active deformation is achieved using a bimorph PZT piezoelectric disk actuator bonded to a glass diaphragm. The bimorph PZT deflects the diaphragm as well as alternately pushing and pulling the elastomer layer providing displacement amplificati...

Beam shaping is becoming increasingly important for synchrotron X-ray applications. Although routine for visible light lasers, this is challenging for X-rays due to the limited source coherence and extreme optical tolerances required for the shaping mirrors. In deliberate defocusing, even surface errors <5 nm r.m.s. introduce damagingly large striations into the reflected beam. To counteract su...

The feasibility of harnessing electric energy using piezoelectric inserts in a sport sneaker has been demonstrated. Continuing in that spirit, this thesis compares regulation schemes for conditioning the electric energy harnessed by a piezoceramic source imbedded in a shoe insole. Two off-line, dc-dc direct converter hybrids (buck and forward) are proposed and implemented to improve the convers...

The potential use of piezoelectric bimorph actuators in minimally invasive surgery suture-needle grasper/holder applications is explored computationally. Upon defining the design/functional requirements for such surgical tools, a finite element analysis of the underlying piezoelectric boundary value problem is combined with the genetic algorithm optimization routine to arrive at an optimal morp...

We consider piezoelectric flow energy harvesting in an internal flow environment with the ultimate goal powering systems such as sensors in deep oil well applications. Fluid motion is coupled to structural vibration via a cantilever beam placed in a converging-diverging flow channel. Two designs were considered for the electromechanical coupling: first; the cantilever itself is a piezoelectric ...