"Long before it's in the papers"
November 21, 2011

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“Terminator”-style info-vision may be closer to reality

March 30, 2005
Courtesy 
and World Science staff

The stream­ing of real-time in­forma­t­ion across your vis­u­al field is a step clos­er to real­ity with the de­vel­op­ment of a new pro­to­type con­tact lens, re­search­ers say.

The de­vice, de­scribed in the Nov. 22 is­sue of the Jour­nal of Mi­crome­chan­ics and Mi­cro­engi­neer­ing, is de­signed with a view to­ward pro­vid­ing wear­ers with hands-free in­forma­t­ion up­dates. The re­search­ers said they built a com­put­erised con­tact lens and dem­on­strat­ed its safe­ty by test­ing it on rab­bits, with no ap­par­ent ill ef­fects.

The lens dis­plays just one pix­el, or dot of light, for now but the re­search­ers see this as a “proof-of-concept” for man­y-pix­el lens­es that could dis­play short mes­sages. The de­vice could over­lay computer-generated vis­u­al in­forma­t­ion on to the real world and be of use in gam­ing de­vices and naviga­t­ion sys­tems, they said; it could al­so be linked to sen­sors in the user’s body to pro­vide up-to-date in­forma­t­ion on health in­di­ca­tors such as glu­cose lev­els.

The con­tact lens, cre­at­ed by re­search­ers at the Uni­vers­ity of Wash­ing­ton and Aal­to Uni­vers­ity, Fin­land, con­tains a ti­ny an­ten­na to har­vest pow­er from an ex­ter­nal source. It al­so con­tains an in­te­grat­ed cir­cuit to store this en­er­gy and trans­fer it to a trans­par­ent sap­phire chip con­tain­ing an il­lu­mina­t­ion de­vice in the form of an LED, or light-emitting di­ode.

A ma­jor prob­lem was that the hu­man eye can’t re­solve ob­jects on a con­tact lens; a nor­mal eye can only fo­cus on ob­jects a bit fur­ther away. In­forma­t­ion pro­jected on the lens would probably look blur­ry. To com­bat this, the re­search­ers in­cor­po­rat­ed a set of so-called Fres­nel lens­es in­to the de­vice; these are ex­treme­ly thin and flat and were used to fo­cus an im­age on­to the ret­i­na of the eye.

Af­ter test­ing the con­tact lens in free space, it was fit­ted to a rab­bit’s eye un­der strict con­di­tions for hu­mane treat­ment, the re­search­ers said. In ad­di­tion to vis­u­alising tech­niques, a flu­o­res­cent dye was added to the eye of the rab­bit to test for any abra­sion or burn­ing. Sig­nif­i­cant im­prove­ments are still needed, the re­search­ers ac­knowl­edged. One prob­lem was that the pow­ering de­vice had to be placed with­in two cen­time­ters (less than an inch) of the rab­bit’s eye.

“We need to im­prove the an­ten­na de­sign and the as­so­ci­at­ed match­ing net­work and op­ti­mize the trans­mis­sion fre­quen­cy to achieve an over­all im­provement in the range of wire­less pow­er trans­mis­sion,” said study co-author Babak Praviz of the Uni­vers­ity of Wash­ing­ton. “Our next goal, how­ev­er, is to in­cor­po­rate some pre­de­ter­mined text in the con­tact lens.”

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The streaming of real-time information across your visual field is a step closer to reality with the development of a new prototype contact lens, researcherssay. The device, described in the Nov. 22 issue of Journal of Micromechanics and Microengineering, is designed with a view toward providing wearers with hands-free information updates. The researchers said they built a computerised contact lens and demonstrated its safety by testing it on rabbits, with no apparent ill effects. The lens displays just one pixel, or dot of light, for now but the researchers see this as a “proof-of-concept” for many-pixel lenses that could display short messages. The device could overlay computer-generated visual information on to the real world and be of use in gaming devices and navigation systems, they said; it could also be linked to biosensors in the user’s body to provide up-to-date information on health indicators such as glucose levels. The contact lens, created by researchers at the University of Washington and Aalto University, Finland, contains a tiny antenna to harvest power from an external source. It also contains an integrated circuit to store this energy and transfer it to a transparent sapphire chip containing an illumination device in the form of an LED, or light-emitting diode. A major problem was that the human eye can’t resolve objects on a contact lens; a normal eye can only focus on objects a bit further away. Information projected on the lens would probably look blurry. To combat this, the researchers incorporated a set of so-called Fresnel lenses into the device; these are much thinner and flatter than bulky lenses, the developers explained, and served to focus an image onto the retina of the eye. After testing the contact lens in free space, it was fitted to a rabbit’s eye under strict conditions for humane treatment, the researchers said. In addition to visualising techniques, a fluorescent dye was added to the eye of the rabbit to test for any abrasion or burning. Significant improvements are still needed, the researchers acknowledged. One problem was that the powering device had to be placed within two centimeters (less than an inch) of the rabbit’s eye. “We need to improve the antenna design and the associated matching network and optimize the transmission frequency to achieve an overall improvement in the range of wireless power transmission,” said study co-author Babak Praviz of the University of Washington. “Our next goal, however, is to incorporate some predetermined text in the contact lens.”