Advanced Materials and Processing

Description of past research & capabilities for Advanced Materials & Processing



Subsurface Imaging of Cracking and Corrosion Under Paints

Applications: Improved structural analysis of metal surfaces, including aircraft, bridges, piers, vehicles, and boats

Project Description: Use optical methods to detect corrosion on a metallic surface or cracks beneath paint. The following techniques are being investigated:

Mid-Infrared (MIR) scanning Imaging: using back reflection geometry we have imaged corrosion and micro-cracks beneath paint layers of thickness to 80-100mm.

Near-infrared (NIR) spectral polarization CCD: results show that corrosion on metals and small cracks underneath paints can be identified through a thickness of paint greater than100 mm.

Femtosecond second harmonic generation (SHG).

Benefits: Quick, environmentally friendly and inexpensive method to determine need for repairs of large painted structures without removing paint



Tunable Multiple Quantum Well GaN/AlGaN UV Photodetectors

Applications: Ultraviolet spectroscopy, florescence and reflectance based instruments for military, medical and industrial uses

Project Description: Develop next generation UV photodetectors with high efficiency and high response speed. These GaN/AlGaN multiple-quantum-well (MQW) photodetectors can be used in space-to-earth and space-to-space communication, missile plume detection, combustion sensing and control for aircraft engines, optical storage, air quality monitoring, and personal UV exposure dosimetry.

Benefits: Higher sensitivity (gain) than currently available devices



Optical and Thermal Conductivity Characterization of GaN, GaAlN and Other Wide Band Gap Semiconductors

Applications: High-power LEDs and long-lifetime lasers

Project Description: Develop techniques and instrumentation for improved detection, characterization and study of structural defects and materials quality in wide band gap semiconductors by measuring high spatial/depth resolution (2-3 mm) thermal conductivity using scanning thermal microscopy and also by various optical methods such as electro modulation (photoreflectance and contactless electro-reflectance) and Raman scattering, including micro-Raman scattering. Determining local thermal properties near defects will enable minimization of local thermal buildup and maximization of overall heat dissipation, which will lead to development of more stable, longer-lived devices.

Benefits: More stable, longer-lived semiconductor devices, high-power LEDs and long lifetime lasers. Improve instrumentation for defect detection.



Colored Photovoltaic Modules Integrated into Building Materials

Applications: Photovoltaic (PV) modules integrated into materials used on building exteriors

Project Description: Create aesthetic, energy-efficient architectural building materials. Current emphasis is on techniques and materials for adding color to PV panels while maintaining cell efficiency. Successful tests indicate that panels using dye-doped polymer films may represent a viable approach.

Benefits: Architecturally viable and efficient electrical solar power generation



Defect Detection in PCB Interconnects

Applications: Quality control, PCB defect management

Project Description: Develop an optical imaging technique and apparatus to nondestructively detect “hard-to-see” defects on PCB interconnect products using photon migration.

Benefits: Reduce inspection costs and waste; increase understanding of PCB failure mechanisms



Cationic Copolymerization

Applications: Consumer products, including paints and coatings, optical recording, textiles, plastics, gears for machinery, fuel tanks and plumbing

Project Description: Develop techniques for synthesis of novel comonomers using cationic copolymerization to form new high-performance engineering plastics with much improved and broader technical applications

Benefits: New materials with better properties for use in plastics, paints, and textiles



Photodeposition of Porous Claddings on Silica Fibers

Applications: Fiber optic temperature, pressure and displacement sensors; switches; modulators

Project Description: Characterize the morphology and porosity of porous silica claddings on micron diameter optical fibers. Obtain optical micrographic pictures of cladding morphology and surface roughness as measured by atomic force microscopy. Determine the porosity of the cladding by doping with Fe(CO)5 and examine photodeposition in the fiber cladding.

Benefits: Very high-resolution sensors and high-speed optical switches. Potential low cost manufacturing technique.