Public release date: 19-Apr-2006
[ | E-mail Article ]

Contact: Claire Bowles
claire.bowles@rbi.co.uk
44-207-611-1210
New Scientist
-->

Solar-powered retinal implant

AN IMPLANT that squirts chemicals into the back of your eye may not sound like much fun. But a solar-powered chip that stimulates retinal cells by spraying them with neurotransmitters could restore sight to blind people.

Unlike other implants under development that apply an electric charge directly to retinal cells, the device does not cause the cells to heat up. It also uses very little power, so it does not need external batteries.

The retina, which lines the back and sides of the eyeball, contains photoreceptor cells that release signalling chemicals called neurotransmitters in response to light. The neurotransmitters pass into nerve cells on top of the photoreceptors, from where the signals are relayed to the brain via a series of electrical and chemical reactions. In people with retinal diseases such as age-related macular degeneration and retinitis pigmentosa, the photoreceptors become damaged, ultimately causing blindness.

Last year engineer Laxman Saggere of the University of Illinois at Chicago unveiled plans for an implant that would replace these damaged photoreceptors with a set of neurotransmitter pumps that respond to light. Now he has built a crucial component: a solar-powered actuator that flexes in response to the very low intensity light that strikes the retina. Multiple actuators on a single chip pick up the details of the image focused on the retina, allowing some "pixels" to be passed on to the brain.

The prototype actuator consists of a flexible silicon disc just 1.5 millimetres in diameter and 15 micrometres thick. When light hits a silicon solar cell next to the disc it produces a voltage. The solar cell is connected to a layer of piezoelectric material called lead zirconate titanate (PZT), which changes shape in response to the voltage, pushing down on the silicon disc. In future, a reservoir will sit underneath the disc, and this action will squeeze the neurotransmitters out onto retinal cells.

###

Author: Celeste Biever

"This article is posted on this site to give advance access to other authorised media who may wish to quote extracts as part of fair dealing with this copyrighted material. Full attribution is required, and if publishing online a link to www.newscientist.com is also required. This story posted here is the EXACT text used in New Scientist, therefore advance permission is required before any and every reproduction of each article in full. Please contact celia.guthrie@rbi.co.uk. Please note that all material is copyright of Reed Business Information Limited and we reserve the right to take such action as we consider appropriate to protect such copyright."

THIS ARTICLE APPEARS IN NEW SCIENTIST MAGAZINE ISSUE: 22 APRIL 2006

IF REPORTING ON THIS STORY, PLEASE MENTION NEW SCIENTIST AS THE SOURCE AND, IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO: http://www.newscientist.com

UK CONTACT - Claire Bowles, New Scientist Press Office, London:
Tel: +44(0)20 7611 1210 or email claire.bowles@rbi.co.uk

US CONTACT New Scientist Boston office:
Tel: +1 617 386 2190 or email kyre.austin@reedbusiness.com


Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
    Published on PsychCentral.com. All rights reserved.

 

 

The privilege of a lifetime is being who you are.
~ Joseph Campbell
 
 
From Our News Bureau
Just Published...
What's Hot
Most Popular News
Most Popular Posts
Subscribe to Our Weekly Newsletter


Find a Therapist
Enter ZIP or postal code



Users Online: 9226
Join Us Now!