MEMS Colloid Thruster Array (TDA Research
Inc. STTR Phase I and II programs funded by AFOSR) - Colloid thruster
technology involves the emission of small droplets using the
electrospray concept. The recent advent of
microelectromechanical systems (MEMS) technology and improved
propellants has created renewed interest in the technology.
Colloid thruster arrays may produce large
thrust levels, while maintaining the ability to deliver a small impulse
bit from a single emitter, making
them well suited to micro- and nano-satellites. However, a number
of technological barriers
have prevented full development at the micro-scale. In
particular, simple fabrication
strategies are needed to create dense two-
dimensional thruster arrays. Therefore, TDA Research, Inc.,
teamed with the University of Colorado at Boulder, has been designing
and fabricating 2D colloid thruster arrays and studying their
Actively Controlled Self-aspirating MEMS Fuel Injector (TDA Research Inc. SBIR funded by NSF) - The liquid fueled carburetor most commonly used in small gasoline fueled engines meters, injects and mixes the fuel with the air flowing to the engine. However, the system cannot time the injection, so the engines suffer from relatively poor fuel economy and high emission levels. Unfortunately, small engines account for significant amounts of HC, CO, NOx, and Particulate Matter emissions, which form smog and contain toxic compounds such as benzene, toluene, formaldehyde, acetaldehyde, and acrolein. Due to this significant amount of pollution, the EPA has mandated emissions regulations for these engines, which existing technology will be unable to meet in a cost effective manner. Therefore, TDA Research and the University of Colorado are developing low-cost MEMS fuel atomizers for timed injection. This Phase I project will determine the feasibility of this new technology and establish a design. In Phase II, we will build prototype MEMS atomizers, integrate them into a four-stroke engine and demonstrate their ability to reduce pollutants to below the planned regulated levels.
Biomass Thermochemical Processing (National Renwable Energy Laboratory) - Thermochemical processing of biomass materials is important for generation of biomass based fuels and other commercially valuable chemical products. When biomass is heated with no oxygen or only about one-third the oxygen needed for efficient combustion (amount of oxygen and other conditions determine if biomass gasifies or pyrolyzes), it gasifies to a mixture of carbon monoxide and hydrogen—synthesis gas or syngas. Other heating strategies can produce liquids, or be optimized for chemicals production. We are studying the chemical kinetics of biomass thermal decomposition to develop chemical mechanisms needed for process control.
Modeling of Laser Excitation Dynamics for LIF Measurement of Small Radicals (In collaboration with Dr. Thomas Settersten of Sandia National Laboratory) - A study of the excitation dynamics of small molecules when excited by a laser for use of laser induced fluorescence (LIF) in combustion and CVD applications. The dynamics are modeled using the time dependent rate equations and compared with pump/probe measurements in low pressure flames and CVD reactors. Current work involves the use of trajectory calculations to obtain rotational energy transfer rates for NO with a variety of collision partners.
Optical Biopsy (In collaboration with faculty at the University of Colorado Health Sciences Center) - Prostate cancer remains the most common visceral cancer and second most common cause of cancer deaths in the United States. It is a disease characterized by a high prevalence and marked heterogeneity of its morphology as well as its clinical behavior. The therapeutic management of patients with this disease requires precise information regarding: 1) the natural history of the disease, and 2) our ability to evaluate the status of the disease prior to radical therapy. Our approach is to utilize a biopsy needle mounted fiber optic array. The fiber array delivers the excitation light and collects scattered light. The simplest methodology involves directly measuring elastically scattered light. Elastic scattering has been used to classify a number of surface cancers, and seems promising. Indeed, preliminary absorption measurements carried out using tissues samples obtained from radical prostatectomy specimens showed clear spectral definition between normal and metastatic tissue. Testing of a more advanced method, laser induced fluorescence, is underway.