PALMER, JEREMY ANDREW. Development of Millimeter Scale Motors For Miniature Direct Drive Robots. (Under the direction of Dr. Edward Grant, and Dr. Jeffrey W. Eischen) The twentieth century marked a period of rapid expansion of technology associated with miniaturization of engineering systems. A recent theme in this trend is the development of miniature, distributed robots that mimic insect beha...

This paper demonstrates a hafnium zirconium oxide (HZO)-based ferroelectric NEMS unimorph as the fundamental building block for very low-energy capacitive readout in-memory computing. The reported device consists of 250 $\mu$m $\times$ 30 cantilever with 20 nm thick HZO on 1 $SiO_2$.Partial switching in achieves analog programmable control piezoelectric coefficient ($d_{31}$) which serves compu...

This work presents a high yield wafer scale fabrication of MEMS-based unimorph silicon/PZT thick film vibrational energy harvesters aimed towards vibration sources with peak frequencies in the range of a few hundred Hz. By combining KOH etching with mechanical front side protection, SOI wafer to accurately define the thickness of the silicon part of the harvester and a silicon compatible PZT th...

A novel surface micromachining process is reported for aluminum nitride (AlN) thin films to fabricate piezoelectric unimorph suspension devices for micro actuator applications. Wet anisotropic etching of AlN thin film is used with a Cr metal mask layer in the microfabrication process. Tetra methyl ammonium hydroxide (TMAH) of 25 wt.% solution is used as an etching solution for the AlN thin film...

Possibilities for the " parasitic " collection of power from human walking motion are explored. The focus is on the walking action as a source of power because of the extensive range of motion and large dynamic forces associated with the heel strike and the bending of the sole. Two piezoelectric systems: a multilayer laminate made from PVDF foil and a unimorph piezoceramic composite (PZT); as w...

In this paper we develop a mathematical model to simulate the actuation of a multilayer metallic strip. In the first step of the model development, we employ the theory of Judy [4] and Timoshenko [5] to quantify the radius of curvature in the unimorph due to differing thermal coefficients in the constituent materials. The resulting radius of curvature is subsequently used to compute the voltage...

Abstract. This paper is a comparative study of the design spaces of two bio-implantable acoustically excited generator architectures: the thickness-stretch-mode circular piezoelectric plate and the bending-mode unimorph piezoelectric diaphragm. The generators are part of an acoustic power transfer system for implanted sensors and medical devices such as glucose monitors, metabolic monitors, dru...

In this paper we investigate the capability of harvesting the electric energy from mechanical vibrations in a dynamic environment through a unimorph piezoelectric membrane transducer. Due to the impedance matrices connecting the efforts and flows of the membrane, we have established the dynamic electric equivalent circuit of the transducer. In a first study and in order to validate theoretical ...