Task Leader:Professor Nai Juan Wu at naijwu@uh.edu
Ceramic optical detectors based on the photo-ferroelectric effect are being developed
for direct implantation into the eyes of patients with retinal dystrophies. In retinal
dystrophies where the optic nerve and retinal ganglia are intact (such as Retinitis
Pigmentosa), direct retinal implant of an optical detector to stimulate retinal ganglia
could allow patients to regain some sight. In such cases additional wiring to the brain
cortex is not required, and for biologically inert detectors, surgical implantation can
be quite direct. The detector currently being developed for this application jointly
with the University of Texas Health Science Center is a thin film ferroelectric detector,
which under optical illumination can generate a local photocurrent and photovoltage.
The local electric current generated by this miniature detector excites the retinal neural
circuit resulting in a signal at the optic nerve that may be translated by the cortex of
the brain as "seeing light". Detectors based on PbLaZrTiO3 (PLZT) and BiVMnO3
(BVMO) films exhibit a strong photoresponse in visible range overlapping eye response
from 380 nm to 650 nm. The thin film detector heterostructures have been implanted into
the eyes of rabbits for biocompatibility test, and have shown no biological
incompatibilities. Optical response test are in progress.
Personnel:
Related Bionic Eye Publications
Last modified: 06 Sep 2001
Dr. Ali Zomorrodian: Research Scientist
Jake Fan: Research Assistant
Space Vacuum Epitaxy Center
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