Research

In this research program, we develop innovative processes to generate nano-coatings. We further investigate mechanisms of tribochemical interactions on surfaces of metals and oxides. Fundamental investigation focuses on new phenomena and non-equilibrium surfaces, including surface forces and wear from nanometer to centimeter length scales, new surface bonds, nonequilibrium crystal structures, non-stoichiometric products, and kinetics of growth. Experimental approaches include using atomic force microscopy (AFM) and table-top tribometery to polish, manipulate, and test materials at different length scales. The primary methods of surface characterization include AFM, TEM, XPS, TOF SIMS, and other high-resolution spectroscopic techniques. Materials studied are strategically selected to reveal principles in effects of electronic, chemical, and crystal structures on friction and wear. This research is at the interface of several scientific and technological areas involving physical, chemical, mechanical, and tribological properties of advanced materials. The outcome of this research is in the development of novel nanostructured materials and nanofabrication processes.

This research focuses on the development of nanofabrication processes. The process generates nanometer length scale phases through simple mechanical or chemical reaction methods. This research includes fundamental and practical aspects. Fundamentally, the structure-surface properties influenced by external energy will be studied. Materials involved in this study are amorphous, nanocrsytalline, and piezoelectric ones. The simplicity and flexibility of the techniques is a significant advantage for synthesis and characterization of nano-structures. The potential applications fall in nanomachining, assembly, nanosensors, and development of MEMS and NEMS.

Related News:

http://engineer.tamu.edu/news/story/?p_news_id=1702

http://www.physorg.com/news121700723.html

http://www.nanowerk.com/news/newsid=4457.php

Despite the success of surgical implants such as artificial hip and knee joints, the materials used in these procedures still do not satisfy the demands of a durable functioning joint. Current synthetic materials, such as stain less steel, titanium alloy, polymers, and ceramic composites, undergo degradation after 10 to 15 years of use. The common failures of joints are several. Wear and particulate debris are the most common ones. This research contains two components. The first component is to study the tribological performance of implant materials using tribological testing and surface characterization techniques. The second component is to synthesize new class of biomaterials combing live cells and conventional biocompatible materials. Beside cell culture experiments and materials testing, the interfaces between cells and materials will be investigated along with the functionality and performance.

In this research, nanocrystalline piezoelectric structures are grown in a novel manner and will be used to create strain sensors which can be applied in a wide range of applications. In this project the focus is using these sensors to detect and study the locomotion of insects. The diminutive size of the insects demands an ability to design circuits which operate at extreme low power levels (and thereby require extremely small and light power sources). The broader application of these techniques will be in the area of hand-held, portable and wearable computers. This project is carried out by interdisciplinary team researchers, Professor Brad Vinson of Entomology and Professor Sunil Khatri of Electrical Engineering. The proposed research project is expected to have an impact on the field of sensing, signal transfer, nanofabrication, entomology, and low-power electronics.

CMP has been a long term interest of our group. We investigate the mechanisms of polishing, planarization, and cleaning. The surface properties and interfacial reactions are studied. Effects of particles, surfactant molecules, as well as micro- and nano-mechanical forces of solids and fluids are studied. Research results help microelectronic industry to understand and optimize manufacturing processes.