School of Electrical, Computer and Energy Engineering
PhD Final Oral Defense
Flexible Electronics and Display Technology for
Medical, Biological, and Life Science Applications
By
Joseph T. Smith
August 15, 2014
2 PM
GWC 305
Committee:
Dr. David Allee (chair)
Dr. Michael Goryll
Dr. Michael Kozicki
Dr. Jennifer Blain Christen
Dr. Aaron Couture
Abstract
This work explores how flexible electronics and display technology can be
applied to develop new biomedical devices for medical, biological, and life science
applications. It demonstrates how new biomedical devices can be manufactured by only
modifying or personalizing the upper layers of a conventional thin film transistor (TFT)
display process. This personalization was applied first to develop and demonstrate the
world’s largest flexible digital x-ray detector for medical and industrial imaging, and the
world’s first flexible ISFET pH biosensor using TFT technology. These new, flexible,
digital x-ray detectors are more durable than conventional glass substrate x-ray detectors,
and also can conform to the surface of the object being imaged. The new flexible ISFET
pH biosensors are >10X less expensive to manufacture than comparable CMOS-based
ISFETs and provide a sensing area that is orders of magnitude larger than CMOS-based
ISFETs. This allows for easier integration with area intensive chemical and biological
recognition material as well as allow for a larger number of unique recognition sites for
low cost multiple disease and pathogen detection.
The flexible x-ray detector technology was then extended to demonstrate the
viability of a new technique to seamlessly combine multiple smaller flexible x-ray
detectors into a single very large, ultimately human sized, composite x-ray detector for
new medical imaging applications such as single-exposure, low-dose, full-body digital
radiography. Also explored, is a new approach to increase the sensitivity of digital x-ray
detectors by selectively disabling rows in the active matrix array that are not part of the
imaged region. It was then shown how high-resolution, flexible, organic light-emitting
diode display (OLED) technology can be used to selectively stimulate and/or silence
small groups of neurons on the cortical surface or within the deep brain as a potential new
tool to diagnose and treat, as well as understand, neurological diseases and conditions.
This work also explored the viability of a new miniaturized high sensitivity fluorescence
measurement-based lab-on-a-chip optical biosensor using OLED display and a-Si:H PiN
photodiode active matrix array technology for point-of-care diagnosis of multiple disease
or pathogen biomarkers in a low cost disposable configuration.