The importance of using renewable and intelligent ways of powering electronics devices is critical. As electrical devices become smaller and more portable the use of batteries for power sources has risen. According to a 2007 report of Computer Law & Security Report “E-junk is the fastest growing waste stream and the threat from spent batteries is growing as the volume in landfills grows.” Along with waste “batteries contain heavy metals or potentially toxic substances which pose dangers to human health and the environment.”The largest manufacturer of batteries, China, creates more than 30.5 billion batteries per year. Unfortunately, during the crude recycling process used “approximately fifty-percent of the lead is lost into the environment” and “lead battery waste can discharge acid into waterways and soil, posing a threat to human health”. Currently, this is a major problem in most developing countries. One way to remove the use of batteries is to take advantage of the natural impulse interaction that occur in nature and by normal human interaction, through the use of piezoelectrics. Piezoelectrics works by applying a mechanical stress on a piezoelectric material such as quartz, the stress then induces a voltage over the material which can be used as an energy source. Piezoelectrics are currently used widely and are relatively inexpensive. The most common use is in lighters to create an electrical arc to ignite the reactant and create a flame. The purpose of this project is to develop a piezoelectric harvesting system for low power electronics and apply the developed system on the University of Washington Hydrosense project and a wireless batteryless keyboard.

Though many wireless sensors use power harvesting to avoid troublesome batteries, traditional methods power sensors via cyclic energy sources (e.g. solar). These energy sources rarely coincide with the sensing source, which in this application is water pressure. WATTR combines the sensing and energy sources to power a wireless, water-pressure sensor for “sensing-source-power” and autonomous operation. That is, energy is generated via a mechanical system when relevant events take place and used to power the water-pressure sensor and wireless transmitter. Components of the harvesting system that do not require original research are the wireless interface (utilizing an off-the-shelf board), generator, and receiver. Significant research has gone into the power harvesting circuit, which must convert intermittent voltage into low, constant current. Also, the mechanical conversion system was prototyped and manufactured to reduce friction and maximize energy generated. Quantitative success is measured in the range of the wireless sensor and the percent of useful data received. In context, the sensor must detect pressure spikes, record that data, and transmit it without significant losses upon receiving the data. Finally, WATTR considers the broader method for sensing-source-power and its applications.

Organic field effect transistor (OFET) research has developed into an intense area of study over the past decade with the fabrication of organic devices that yield charge carrier mobilities surpassing that of amorphous silicon. The properties of the semiconducting materials used in the creation of OFETs, gives rise to new processing techniques allowing for the potential creation of low cost, flexible, solution processed electronic devices. By controlling molecular structure, morphology of layers, and device architecture, we hope to achieve the ability to predictably tune electronic properties in OFETs, while utilizing the aforementioned low cost production methods.

We have designed an Atomic Force Microscope (AFM) system capable of operating at temperatures between 20K and 500K and in vacuum below 10^-6 Torr. An AFM uses an ultra-sharp tip to image materials on the nano-scale. With the implementation of scattering Scanning Near-field Optical Microscopy (s-SNOM), we can measure the optical response of nano-scale materials and structures with an optical and spatial resolution of 10nm. A pulsed infrared laser is focused onto the tip (pulse duration ~200 femtoseconds), and the tip-scattered near-field radiation is analyzed interferometrically. The laser pulses are generated using a mode-locked titanium-sapphire laser, and converted to tunable mid-infrared light using an Optical Parametric Oscillator (OPO) and Difference Frequency Generation (DFG). The instrument allows for spectroscopic nanoimaging of the plasmon response of nano-structures, or the different crystal phases in nano-wires. Vanadium oxides wires, for example, undergo a metal to insulator transition at specific low temperatures, switching from the monoclinic M1 phase to the metallic rutile phase. Studying vanadium oxides will give insight into other strongly correlated electron materials, an interesting and newly developing material family. In this talk, I will discuss the design, construction, and scientific principles of our system. I will also review preliminary data and discuss upcoming experiments on the instrument.

In the field of force spectroscopy, the need to measure forces and lengths on the nano-scale is often met with an atomic force microscope (AFM). The purpose of this project was to design a software package for position-based control of AFMs. Through feedback control loops, the software (written in Igor Pro, copyright WaveMetrics, Inc) allows the user to directly control the cantilever position. This is crucial for distance or speed-dependent situations. One useful function is the ability to drive the cantilever through any custom path. This tool has many applications, such as elasticity analysis, due to the direct control of position and strain. To test the software's abilities, the mechanics of type 1 bacterial fimbriae were analyzed. A better understanding of the relationship between fimbrial structure and function could lead towards development of a useful adhesive for mammalian tissues. Site-directed mutagenesis in Escherichia coli K-12 was designed to disrupt the fimbrial ability to naturally coil. Previous studies suggest that improperly coiled fimbriae have a decreased capacity to adhere to surfaces. Mutation efficacy was determined based on the fimbrial characteristics, and the role of structure in cellular surface-adherence was further investigated.