Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-17T19:30:10.116Z Has data issue: false hasContentIssue false
  • English
  • Français

Novel Micro-Photodiodes for Retina Stimulation

Published online by Cambridge University Press:  17 March 2011

M. Rojahn  and
M.B. Schubert
M. Rojahn
Affiliation:
Univ. of Stuttgart, Institute of Physical Electronics, Pfaffenwaldring 47, D-70569 Stuttgart, Germany
M.B. Schubert
Affiliation:
Univ. of Stuttgart, Institute of Physical Electronics, Pfaffenwaldring 47, D-70569 Stuttgart, GermanyEmail:martin.rojahn@ipe.uni-stuttgart.de
Get access

Abstract

We present a new design of micro-photodiodes for in-vitro tests to electrically stimulate the ganglion cells of chicken and rat retinae upon light exposure of the photodiodes. Based on amorphous silicon, our laterally series connected double-stacked micro-photodiodes provide an open circuit voltage of 2.3 volts. Photolithographic steps as well as etching procedures for patterning the back contact, the amorphous silicon layers and the front contact are described. We analyse current- voltage-measurements performed with direct contact of the metal needles of a micro-positioning system to the device's electrodes. In order to test the performance of an individual micro-photodiode in an electrolyte environment, the stimulation electrode of the device is also contacted with a micro-droplet of buffer solution. Further improvement is needed, mainly addressing the problem of long-term stability of the device in electrolyte environments.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 609: Symposium A – Amorphous & Heterogeneous Silicon Thin Films – 2000 , 2000 , A21.4
Copyright
Copyright © Materials Research Society 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Chow, A. Y., Electrical stimulation of the rabbit retina with subretinal electrodes and high density microphotodiode array implants, Investigative Ophthalmology & Visual Science 34, 835 (1993); A.Y. Chow, Artifical retina device, US. Patent No. 5,016,633 (1989)Google Scholar
[2] Chow, A.Y., Chow, V.Y., Subretinal electrical stimulation of the rabbit retina, Neuroscience Letters 225, 13 (1997)Google Scholar
[3] Zrenner, E., Miliczek, K.-D., Gabel, V.P., Graf, H.G., Guenther, E., Hämmerle, H., Höfflinger, B., Kohler, K., Nisch, W., Schubert, M., Stett, A., Weiss, S., The development of subretinal microphotodiodes for replacement of degenerated photoreceptors. Ophthalmic Research 29, 269 (1997)Google Scholar
[4] Zrenner, E., Stett, A., Weiss, S., Aramant, R.B., Guenther, E., Kohler, K., Miliczek, K.-D., Seiler, M.J., Hämmerle, H., Can subretinal microphotodiodes successfully replace degenerated photoreceptors, Vision Research 39, 2555 (1999)Google Scholar
[5] Schubert, M.B., Hierzenberger, A., Baumung, V., Wanka, H.N., Amorphous Silicon Photodiodes for Replacing Degenerated Photoreceptors in the Human Eye, Mat. Res. Soc. Symp. Proc. 467, 913 (1997)Google Scholar
[6] Koch, C., Ito, M., Schubert, M.B., Werner, J.H., Optimization of amorphous silicon solar cells at deposition temperatures below 100°C, Mat. Res. Soc. Symp. Proceed. 557, PAGE???, 1999 Google Scholar
[7] http://www.nmi.deGoogle Scholar
[8] http://www.ims-chips.deGoogle Scholar
[9] Stett, A., Tepfenhart, M., Kohler, K., Nüsslin, F., Hämmerle, H., Zrenner, E., Charge sensitivity of electrically stimulated chicken and RCS rat retinae, Invest. Ophthalmology & Visual Science 40, 734 (1999)Google Scholar
[10] Weiss, S., Herrmann, T., Stett, A., Hämmerle, H., Analysis of field potentials and spike patterns evoked by local electrical stimulation of the chicken retina, in: Hollyfield, J.G., Anderson, R.E., LaVail, M.M. (eds.) Retinal Degenerative Diseases and Experimental Therapy, Plenum Press (in press)Google Scholar