Augmented Reality Contact Lens Startup Develops Apps With Early Adopters-to-Be

Not quite “eyesight to the blind,” but Mojo Vision and nonprofit partner collaborate on assistive sight-enhancement for visual impairments

4 min read
Real world and overlay
Augmented reality contact lenses that highlight the edges of objects can help people with low vision navigate the real world around them
Image: Mojo Vision

Last year, startup Mojo Vision unveiled an early prototype of a contact lens that contains everything it needs to augment reality—an image sensor, display, motion sensors and wireless radios all safe and comfortable to tuck into your eye.

These days, the company’s engineers are “charging hard on development” says Steve Sinclair, Mojo Vision’s senior vice president of product and marketing. While most of Mojo Vision’s hundred employees are working at home, the pandemic only minimally affected the company’s ability to use its laboratories and clean room facilities as needed. The company’s engineers, for instance, are helping a vendor of motion sensors thin its dies for better wearability, partnering with a battery manufacturer to build custom batteries, and refining their own designs of displays, image sensors, and power management electronics. And Mojo last year signed an agreement with Japanese contact lens manufacturer Menicon to fine-tune the materials and coatings of the lens itself.

About a dozen of the company’s employees have worn early prototypes of its lenses. The next generation of prototypes, now under development, is expected to be ready for such testing later this year.

While commercial release is still a few years out, requiring FDA approval as a medical device, development of the first generation of applications is well underway. While Sinclair says the company long anticipated that the earliest adopters of its AR contacts would be the visually impaired, exactly what applications would be useful wasn’t fully clear.

Ashley Tuan, Mojo Vision’s vice president of medical devices, has a personal interest in the technology—her father has limited vision, due to a rare retinal degeneration disease.

With a Ph.D. in vision science, Tuan has also studied the biology. People with low vision, she says, “can’t see fine detail because photoreceptors have died. That is typically solved with magnification, though people generally don’t like to carry a magnifier around. They also have an issue with contrast sensitivity, that is, the ability to sense light grey, for example, from a white background. This can stop them from going into unfamiliar surroundings because they don’t feel safe. Most of us subconsciously use shadows to identify something coming up, something that we might trip over. In studies, even a slight reduction in contrast sensitivity stops people from going outside.”

Mojo Vision is developing apps to address these issues. “Enhancing contrast is easy to do with our technology,” Tuan says. “Because we are projecting an image onto the retina, we can easily increase the contrast of that image.

“We can also do edge detection, which I see as being one step above contrast enhancement, by highlighting the edges of objects with light.”

Mojo Vision has these tools implemented in prototypes. In the future, Tuan expects the technology will evolve to adjust what it is highlighting according to the context—a street sign, perhaps, or the facial expressions of someone talking to the wearer.

Magnification, with the current prototype, is triggered by the user zooming using the image sensor. In the future, the company expects to make magnification context dependent as well, with the system determining when a wearer is looking at the menu in a restaurant and therefore needs magnification, or looking for the bathroom, and instead needs the letters of the sign and the frame of the door brightened.

Mojo Vision’s development team is now trying to take these basic ideas for apps and turn them into something that they hope will be immediately useful for their early adopters. To do that, they turned to a Silicon Valley resource, the Palo Alto Vista Center’s Corporate Partners Program.

Says Alice Turner, Vista Center’s director of community and corporate relations: “We have been working with tech companies in the product design realm for about three years, about eight to ten companies so far, including Facebook, Microsoft, Samsung, and other companies that haven’t announced products yet. I know partnering with us results in a better product, better suited, and the population that it is addressing will be better served.”

“Mojo Vision,” she says, “is a huge success story for our partnership program.”

The tech tools that eventually come to market through this program help some of Vista Center’s clients. But the program also provides more immediate benefits; the fees it charges the companies provide a steady source of revenue for the nonprofit.

When brought in on a product development project by a tech company, Turner taps into Vista Center’s client database, some 3400 individuals representing a wide range of vision impairments and demographics. She selects people who are appropriate matches for the technology under development, confirms that they have some basic tech skills and are comfortable talking freely about their condition and experiences, and sets up one-on-one meetings (virtual in these pandemic times) and focus groups during which the developers can get feedback for anything from an idea to a rough demo to a working prototype.

David Hobbs, director of product management at Mojo Vision explained that, for Mojo, the process started with interviewing to find out more about problems that the technology could potentially solve. After identifying the problems, the team brought a subset of Vista’s clients in for a deeper dive.

“For example,” he said, “When we are trying to understand how to cross a crosswalk, we may talk for hours about different crosswalk situations.”

Then the Mojo Vision design team builds prototype software for use with customized virtual reality headsets. The Vista clients test the prototype software and give feedback. The company will do clinical trials with lens prototypes after it gets FDA Breakthrough Device approval.

“We are learning,” Hobbs said, “that vision is uniquely intimate. Everyone sees differently, so finding a way to provide the information that someone wants in the way they want it is really challenging. And different scenarios require different levels of detail and context.”

While this development process continues, the Mojo Vision developers have already learned from the tests conducted so far.

“When we looked at edge detection,” Hobbs said, “we were just taking an image and, wherever there was a lot of difference between two pixels, drawing a line. We created detailed models of the world  in this way. Our bias was that all of this detail was valuable.

“But the feedback we got was all these lines were a lot of noise,” he continues. “It turns out that there is a level of information that we can provide that can help people on their journey without being overwhelming.”

Hobbs expects many the AR applications developed for the visually impaired to evolve into technology useful for everyone. “Fulfilling the needs of the most demanding users provides a lot of capabilities for general users as well. Take the ability to see in the dark. Going into a dark stairwell and having enhanced vision flip on would be valuable to many.”

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The Inner Beauty of Basic Electronics

Open Circuits showcases the surprising complexity of passive components

5 min read
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A photo of a high-stability film resistor with the letters "MIS" in yellow.
All photos by Eric Schlaepfer & Windell H. Oskay
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Eric Schlaepfer was trying to fix a broken piece of test equipment when he came across the cause of the problem—a troubled tantalum capacitor. The component had somehow shorted out, and he wanted to know why. So he polished it down for a look inside. He never found the source of the short, but he and his collaborator, Windell H. Oskay, discovered something even better: a breathtaking hidden world inside electronics. What followed were hours and hours of polishing, cleaning, and photography that resulted in Open Circuits: The Inner Beauty of Electronic Components (No Starch Press, 2022), an excerpt of which follows. As the authors write, everything about these components is deliberately designed to meet specific technical needs, but that design leads to “accidental beauty: the emergent aesthetics of things you were never expected to see.”

From a book that spans the wide world of electronics, what we at IEEE Spectrum found surprisingly compelling were the insides of things we don’t spend much time thinking about, passive components. Transistors, LEDs, and other semiconductors may be where the action is, but the simple physics of resistors, capacitors, and inductors have their own sort of splendor.

High-Stability Film Resistor

A photo of a high-stability film resistor with the letters "MIS" in yellow.

All photos by Eric Schlaepfer & Windell H. Oskay

This high-stability film resistor, about 4 millimeters in diameter, is made in much the same way as its inexpensive carbon-film cousin, but with exacting precision. A ceramic rod is coated with a fine layer of resistive film (thin metal, metal oxide, or carbon) and then a perfectly uniform helical groove is machined into the film.

Instead of coating the resistor with an epoxy, it’s hermetically sealed in a lustrous little glass envelope. This makes the resistor more robust, ideal for specialized cases such as precision reference instrumentation, where long-term stability of the resistor is critical. The glass envelope provides better isolation against moisture and other environmental changes than standard coatings like epoxy.

15-Turn Trimmer Potentiometer

A photo of a blue chip
A photo of a blue chip on a circuit board.

It takes 15 rotations of an adjustment screw to move a 15-turn trimmer potentiometer from one end of its resistive range to the other. Circuits that need to be adjusted with fine resolution control use this type of trimmer pot instead of the single-turn variety.

The resistive element in this trimmer is a strip of cermet—a composite of ceramic and metal—silk-screened on a white ceramic substrate. Screen-printed metal links each end of the strip to the connecting wires. It’s a flattened, linear version of the horseshoe-shaped resistive element in single-turn trimmers.

Turning the adjustment screw moves a plastic slider along a track. The wiper is a spring finger, a spring-loaded metal contact, attached to the slider. It makes contact between a metal strip and the selected point on the strip of resistive film.

Ceramic Disc Capacitor

A cutaway of a Ceramic Disc Capacitor
A photo of a Ceramic Disc Capacitor

Capacitors are fundamental electronic components that store energy in the form of static electricity. They’re used in countless ways, including for bulk energy storage, to smooth out electronic signals, and as computer memory cells. The simplest capacitor consists of two parallel metal plates with a gap between them, but capacitors can take many forms so long as there are two conductive surfaces, called electrodes, separated by an insulator.

A ceramic disc capacitor is a low-cost capacitor that is frequently found in appliances and toys. Its insulator is a ceramic disc, and its two parallel plates are extremely thin metal coatings that are evaporated or sputtered onto the disc’s outer surfaces. Connecting wires are attached using solder, and the whole assembly is dipped into a porous coating material that dries hard and protects the capacitor from damage.

Film Capacitor

An image of a cut away of a capacitor
A photo of a green capacitor.

Film capacitors are frequently found in high-quality audio equipment, such as headphone amplifiers, record players, graphic equalizers, and radio tuners. Their key feature is that the dielectric material is a plastic film, such as polyester or polypropylene.

The metal electrodes of this film capacitor are vacuum-deposited on the surfaces of long strips of plastic film. After the leads are attached, the films are rolled up and dipped into an epoxy that binds the assembly together. Then the completed assembly is dipped in a tough outer coating and marked with its value.

Other types of film capacitors are made by stacking flat layers of metallized plastic film, rather than rolling up layers of film.

Dipped Tantalum Capacitor

A photo of a cutaway of a Dipped Tantalum Capacitor

At the core of this capacitor is a porous pellet of tantalum metal. The pellet is made from tantalum powder and sintered, or compressed at a high temperature, into a dense, spongelike solid.

Just like a kitchen sponge, the resulting pellet has a high surface area per unit volume. The pellet is then anodized, creating an insulating oxide layer with an equally high surface area. This process packs a lot of capacitance into a compact device, using spongelike geometry rather than the stacked or rolled layers that most other capacitors use.

The device’s positive terminal, or anode, is connected directly to the tantalum metal. The negative terminal, or cathode, is formed by a thin layer of conductive manganese dioxide coating the pellet.

Axial Inductor

An image of a cutaway of a Axial Inductor
A photo of a collection of cut wires

Inductors are fundamental electronic components that store energy in the form of a magnetic field. They’re used, for example, in some types of power supplies to convert between voltages by alternately storing and releasing energy. This energy-efficient design helps maximize the battery life of cellphones and other portable electronics.

Inductors typically consist of a coil of insulated wire wrapped around a core of magnetic material like iron or ferrite, a ceramic filled with iron oxide. Current flowing around the core produces a magnetic field that acts as a sort of flywheel for current, smoothing out changes in the current as it flows through the inductor.

This axial inductor has a number of turns of varnished copper wire wrapped around a ferrite form and soldered to copper leads on its two ends. It has several layers of protection: a clear varnish over the windings, a light-green coating around the solder joints, and a striking green outer coating to protect the whole component and provide a surface for the colorful stripes that indicate its inductance value.

Power Supply Transformer

A photo of a collection of cut wires
A photo of a yellow element on a circuit board.

This transformer has multiple sets of windings and is used in a power supply to create multiple output AC voltages from a single AC input such as a wall outlet.

The small wires nearer the center are “high impedance” turns of magnet wire. These windings carry a higher voltage but a lower current. They’re protected by several layers of tape, a copper-foil electrostatic shield, and more tape.

The outer “low impedance” windings are made with thicker insulated wire and fewer turns. They handle a lower voltage but a higher current.

All of the windings are wrapped around a black plastic bobbin. Two pieces of ferrite ceramic are bonded together to form the magnetic core at the heart of the transformer.

This article appears in the February 2023 print issue.

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