Our Design
Equipment and Materials
Carbon Nanotube Covering
The tissue around the eye is sensitive, and it is important to consider that certain materials used as the covering of the bionic eye may cause irritation or negative side effects. A carbon nanotube covering is the most logic solution for serving as the outer layer of the bionic eye as well as the structure of the actual eye itself. This type of covering would not only be perfect because carbon nanotubes behave like human skin, but also because they are biocompatible, meaning that the human body will not reject the bionic eye or irritate the surrounding tissue.[1] Carbon nanotubes are also sturdy enough to serve as the structure of the eye, due to its strong chemical bonds.[2] Because of these reasons, this makes the use of carbon nanotubes ideal for the production of the bionic eye.
Aperture
Aperture acts as the control of light going into the eye. The pupil minimizes when light increases. Also when light decreases the pupil is widen so that only available light can enter. It also determines how much light enters the eyes and how the rays that enter shape the image. It will show if the image is narrow, widen, light, or darker so provide a sense of clear image.
An optical system usually has many openings that limit ray bundles. These structures would be a fixture that would hold the optical element in place or could be a diaphragm placed in the optical place to limit the light admitted by the system. These structures are usually called aperture[3] stop that determine brightness at an image point. This would be in the bionic eye to help minimize and maximize the light coming into eyes. The point of this is to determine the images brightness and also darkness and make the image clearer.
Lens
A transparent thin silicone disk[4] will be used to make the lens of the bionic eye. It's flexible like the real lens in the human eye, and it can be manipulated in order to focus on objects close to the eye and objects far away from the eye. This will allow the bionic eye to see things in a way similar to a real human eye.
Artificial Cones and Rods
Currently a special type of ceramic film is being developed by the Space Vacuum Epitaxy Centre located in Texas. This photosensitive material is potentially able to restore some patients who have lost their vision. The ceramic microdetectors are basically artificial light sensors that send electrical signals to the electrodes, which then send the information on to the brain. The microdetectors are 1/20th the size of human hair, and can be placed in a pattern similar to the configuration of real cones and rods in the human eye. This lining of ceramic photoreceptors around the "retina" of the bionic eye would grant the user color vision, with the photosensitive film acting as the artificial cones and rods of the bionic eye. As of right now, the ceramic microdetectors have yet to be tested on human beings, but with more development of it, the microdetectors could be used in the bionic eye and fully emulate the cones and rods of the human eye.[5]
Electrodes
An electrode is defined as a conductor through which an electrical current can be passed. Electrodes are most commonly made of metals like copper or zinc.
Electrodes are stimulated in accordance with the dark and light sections of the image being seen, generating electrical signals, which travel as neural signals to the brain. This works in a similar way to the retina's photoreceptors, which identify color in an image in a human eye. Once the signals reach the brain, through the path of optic nerves, the brain can decipher the image.[6]
In one test, done in the University of California, Los Angeles, sixteen electrodes were used in each one of six bionic eye. One bionic eye was implanted in each of six subjects, and all regained a small portion of their sight by the end of the test.[7]
Battery or Power Source
The battery's energy comes from the process of converting particles emmitted by radioactive isotopes into motion. This would be ideal for powering the bionic eye, since it would generate electricity, which would be in a form more suitable for circuits.
The battery itself is made of copper strip cantilevered above a thin film of radioactive nickel-63[8] that emits beta particles. The emitted electrons collected would then gather on the copper strip, building up a negative charge. The attraction between the positive and negative charge would bend the strip towards the isotope until a current would flow to equalize the charge. The main advantage of this type of battery is that radioactive isotopes can release energy from days to decades. This would mean that the bionic eye would never have to be recharged, making it functional for the user's lifetime.
The specific radioactive isotope that could be used for the bionic eye is nickel-63[9], which has a half-life of over 100 years, eliminating the need for the bionic eye to be recharged.[10]
Return to Table of ContentsFunctionality
Strength of Vision
Basically, a metal plate with electrodes is attached to the retina in the back of the bionic eye. A camera sends images to the electodes, which then send send the images to the brain through the optic nerve. Because of this, we can conclude that based on how many electrodes there are, the better the vision is. 16 electrodes can allow the user to recognize a plate or a cup. There are also bionic eyes with 60 electrodes which allow clearer images. As of now, Californian scientists are making an implant of 1,000 electrodes, allowing faces to be recognizable.
Bionic Eye Versus Human Eye
The bionic eye is designed to aid those who have lost their vision and give them some of their sight back. Artificial cones and rods send images to the electrodes, which then send send the images to the brain through the optic nerve.
Because of this, we can conclude that based on how many electrodes there are, the better the vision is. Sixteen electrodes can allow the user to recognize a plate or a cup. There are also bionic eyes with 60 electrodes which allow clearer images.[11]
The human eye is at a risk of getting diseases such as astigmatism, but the bionic eye is immune to such diseases. Since the operation for the bionic eye involves surgically attaching the bionic eye into the eye socket of the user, it would be a useful tool for life. The bionic eye is made to fulfill the role the real eye can't: giving people the gift of sight.[12]
Design (how everything fits together)
How Does It Work?
The bionic eye will go through three stages to mimic the vision of a human eye.
First, light will enter into the eye through a transparent area similar to the human eye's cornea. The light will reach the bionic eye's aperture, a mechanism used in cameras to control the amount of light in the photograph. This acts as the iris of the bionic eye, and adjusts according to the intensity of the light, opening wider in a darker environment, and shrinking in an excessively bright environment.
After passing through the aperture, the light will be refracted through the silicone lens, which is flexible and can be controlled by the user to allowing the user to focus on objects far away or up close. The refracted light will then be projected onto the retina area of the bionic eye by the lens. It is here where the ceramic microdetectors will interpret the light as data, fulfilling the role of the cones and rods of the human eye.
The information gathered by the ceramic microdetectors will be sent to the electrodes at the back of the bionic eye. Electrodes take the place of the optic nerve, and transmits information from the bionic eye to the brain. This, creates the link between the bionic eye and the brain, allowing information to be passed onto the brain, where the brain will interpret the information as vision, granting the user the ability to see.
Economic Accessibility
Production and Estimated Cost
Creating bionic eyes is the goeal and it should have a mass close to the real eye, which would be 7.5 grams. A single bionic eye could cost up to $7957, and a set of bionic eyes for an individual would cost $15919. This is a reasonable cost for a device that could enable a person the ability to see the world.
The carbon nanotube covering which would contain the eye and be compatible with the skin will have a mass of 5.77 grams, and the estimated total cost of the carbon nanotube covering would be $100.
Silicone disk is a thick, but flexible material for the formation of the lens in the bionic eye. The silicone lenses have a radius of 4.7 millimeters and thickness of 4 millimeters. The estimated cost of the silicone lens is $30.
The aperture is part of the bionic eye allowing light be seen by the eye and letting it through, so that the eye and be able to enable vision in light and dark places. It is a structure of the eye having a radius of 5 millimeters and thickness of 2 millimeters. The central opening will be adjustable with a maximum opening diameter of 3 millimeters. Rods extending from the aperture system will be able to manipulate the lens. The cost of the aperture will be about $27.
The ceramic microdetector film located in the retina portion of the bionic eye is difficult to manufacture and could be difficult. The overall cost could be up to $3000.
The electrodes will be located on the back of the bionic eye and have an estimated cost of $900.
The special miniature battery powered by nickel-63 is expensive to produce and a costly addition to the bionic eye. The battery, which takes up 1 cubic millimeter of space, will be attached to the aperture structure, which is powered by the battery. Powering the eye by nickel-63 could last more than the half-life of it which can be about 50 years, this is so a person won't have to recharge the battery. The estimated price of this piece of technology is around $3900.
Materials |
Cost |
Carbon Nanotubes Covering |
$100 |
Silicone Disk |
$30 |
Aperture |
$27 |
Ceramic Microdetector |
$3000 |
Electrodes |
$900 |
Battery (uses nickel-63) |
$3900 |
Total (per eye) |
$7957 |