Experimental contact lens contains

Update miniature optoelectronic components

Babak Parviz Ocular

Devon Schuyler Dr Parviz and his team specialise in nanotechnology and micromachining. He said ENGINEERS have developed an that another project he’s working on is a experimental contact lens with tiny flexible computer display that could be electronic components inside.The lens has rolled up and tucked in a pocket. only been placed in rabbit eyes, but the researchers hope that the technology could How realistic? someday be used to create personal virtual displays or even monitor a person’s health Some scientists have expressed scepticism via the eye’s surface. about whether an electronic contact lens “We’ve shown that you can put high- would be able to produce visible images, performance silicon electronic components, noting that the cornea is simply too close to photodetectors, and LEDs on a thin, flexible, the retina for a device placed there to create transparent plastic substrate,” said Babak an image. Parviz PhD, an assistant professor of But Dr Parviz said that projecting the electrical engineering at the University of image about a foot in front of the user Washington in Seattle, who heads the team would solve the problem. developing the device. Inactivate prototypes “Even though the pixels are right on the containing micron-scale metal structures eye, we can manipulate the light rays to A prototype contact lens with embedded micron-scale metal create the impression that the image is necessary to make circuits and antennas circuit interconnects caused no problems when placed in rabbits’ further away so you can focus on it,” he said. eyes for up to 20 minutes. Still, Dr Parviz said he doesn’t wish to Dr Parviz said that the next step, which group’s research at the Institute of Electrical oversell his lab’s accomplishments. Many should begin “fairly soon”, is to activate the and Electronic Engineers’ international people have the misimpression, for example, LED while the device is in the rabbit’s eye. conference on Micro Electro Mechanical that his team has already developed a fully After that, he would like to gain approval to Systems in Tucson,Arizona. functional high-resolution wireless display. begin testing the device in people using a “We don’t have the final product; what we single LED. Components and manufacturing have is the key technologies for eventually “This is really in direct contact with the building it,” he said. The contact lens is made of polyethylene Because the technology has many eye, so we want to be 100 per cent sure terephthalate encased in polymethyl that there are no adverse effects,” he said. potential applications related to vision and methacrylate, the material used to make better understanding of the eye’s physiology, standard rigid gas-permeable lenses. Potential uses Dr Parviz said that he would be happy to The electronic components include the discuss his techniques with any Dr Parviz said that he hopes to use the lens LEDs, which measure one third of a ophthalmologists who would like to learn to create a high-resolution display that millimetre in diameter, and the electronic more. would appear about one foot in front of the circuits and an antenna, which are only a few user.The display would be superimposed on nanometres thick.The LEDs are mounted in [email protected] the outside world to create a hybrid image. the centre of the lens, over the transparent Such a display could replace the screen on part of the eye, and the other components mobile electronic devices such as mobile are away from the centre. phones, laptop computers, and personal “There’s plenty of room on the surface of digital assistants. the eye to place these without interfering “If you could remove the display screen with vision,” he said. from a cell phone, you could make it a lot The device doesn’t contain a battery, so smaller,” he said. the antenna could be used to transmit Other potential applications for this type energy from an external unit.Alternately, the of high-resolution display would be in gaming power could come from solar cells, like a and alternate reality. Players could be light-powered calculator, and the antenna completely immersed in a virtual world could be used for transmitting data. without needing to wear goggles or be The researchers create the prototypes in tethered in any way. a specialised microfabrication laboratory Drivers and pilots might benefit from using a self-assembly process they created having critical information projected directly themselves. on their eyes. The process is based on a capillary Finally, Dr Parviz pointed out that the interaction between the parts and where lenses could contain biochemical sensors for they assemble. Instead of using glue, the continuous, non-invasive monitoring of the researchers etch small shapes in the plastic surface of the eye.The eye’s surface, he said, and rely on metal alloys on the electronic contains live cells that are in indirect contact components to create the bond, he with the blood serum. explained. “If you could sample the biochemical He said that the device is clearly visible on environment of the corneal surface of the the eye’s surface, although eventually the eye, you could get a sense of what’s going on components could theoretically be small inside.The results could be wirelessly enough to blend into the eye.The team transmitted to another device.” hopes to make the device as comfortable as Harvey Ho, a former graduate student at any gas-permeable contact lens, so that it the University of Washington, presented the could be worn for hours at a time.

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