Mojo Vision Puts Its AR Contact Lens Into Its CEO’s Eyes (Literally)

Amazon helps develop an app for the augmented reality contact lens

7 min read
closeup of eye with contact lens containing electronic components

Mojo Vision CEO Drew Perkins wears one of the company’s augmented reality contact lenses.

Mojo Vision

Update 3 November 2022: Today, Mojo Vision announced the first major third-party consumer application to be tested on the prototype of its AR contact lens: the Alexa Shopping List. Developed with support from Amazon, the app allows users to ask Alexa, by talking, to add items to a shopping list that they can then view as a scrollable list through the lens while walking through the grocery store. Users can check off items by holding their gaze for a moment. The list updates in real time if another household member adds items to the shopping list.

Is this the killer app for this augmented reality device? No. But the development does show that major companies are taking Mojo Vision’s smart contact lens seriously.

In March, I looked through Mojo Vision’s AR contact lens—but I didn’t put it in my eye. At that point, while nonworking prototypes had been tested for wearability, nobody had worn the fully functional, battery-powered, wirelessly communicating, device. Earlier this year, Mojo announced that its augmented reality lens had gone on-eye—specifically, on the eye of the Mojo Vision CEO, Drew Perkins, on 23 June.

“I’ve worn it. It works...and it was the first ever on-eye demonstration of a feature-complete augmented reality smart contact lens,” reported Perkins in a blog post. “The final technical hurdle to wearing the lens was ensuring that the power and radio communications systems worked without wires. Cutting the cord [proved] that the lens and all major components are fully functional and reduce many of the technical challenges in building a smart contact lens.”

It’s an exciting milestone for Perkins and the Mojo Vision team, and we’ll continue monitoring their progress.

Story from 30 March 2022 follows:

Two fingers hold a contact lens with a ring of circuitry on its outer edgeEarly this year, IEEE Spectrum editor Tekla Perry tested Mojo Vision's AR contact lens by holding it very close to one eye and peeking through.Mojo Vision

In March,Mojo Vision unveiled its latest AR contact lens. Still a prototype, the device has clinical testing and further development ahead before it can apply for the U.S. Food and Drug Administration (FDA) approval needed to sell to consumers. But Mojo’s engineers are steadily ticking off engineering milestones.

Last week I got to literally peek through Mojo’s newest lens. Here’s what I saw, and what Steve Sinclair, Mojo senior vice president of product and marketing, had to say about the company’s progress so far and the challenges that remain.

First, the demo. I did not put the lens in my eye—this prototype is still in safety testing, and fitting a contact lens requires an eye exam. Instead, I held a lens very close to one eye and peeked through. I was able to move around freely, but because holding instead of wearing the device means that it cannot track eye movements, Mojo has temporarily incorporated a tiny crosshair into the user interface to help with alignment. The nature of the demo also meant that images I saw were flat; with a lens in both eyes, the images will appear in 3D.

What’s New in the Mojo Lens

• Medical-grade microbatteries on board along with a custom power management IC

• High-res 14,000 pixels per inch monochrome microLED display (up from about 8,000 pixels per inch)

• Custom 5-gigahertz radio using a proprietary low-latency communications protocol

• Eye tracking using accelerometer, gyroscope, and magnetometer

• Coming soon: Custom image sensors

I tried out several applications. To select them, I looked around the periphery of the real-world view in front of me, which caused icons to appear. By focusing on one (in this case, aligning the crosshairs), I selected it. The app I found to be the most fun to use wasn’t the most complex, but it did show off the sensors on board by tagging compass headings as I turned to face different directions. I also played with a travel tools app that included a high-resolution monochrome image of an incoming Uber driver, a biking app that called up heart rate and other information useful on a training ride, a teleprompter app that naturally scrolled up and down to move through the text, and a monochrome video stream. All these demos took place in the prototype lens, with me fully in control of them. Mojo’s team then moved to a VR simulation to demonstrate eye tracking features that won’t work unless the lens is sitting in your eye.

This isn’t the first time I’ve seen the Mojo lens in person. But since that last demo in 2020, the engineering team has moved from wireless power to batteries on board, increased the resolution of the display from 8,000 pixels per inch to 14,000, thinned commercial motion sensors and developed its own radio and power management, and created several apps. Image sensors—a feature of earlier demos that showed off edge detection in low light and other vision enhancements—have yet to be built into the current prototype, though Sinclair says that they are in the works, and that the company is continuing to test apps for people with low vision and still expects them to be among the earliest customers for the device.

Here’s what else Sinclair had to say about the technology as developed so far and the path ahead.

Let’s talk about the batteries.

Man from shoulders up smiling, wearing glasses and blue collared shirt

Steve Sinclair

Mojo Vision

Steve Sinclair: The battery is in the outer ring, embedded in the lens. We are partnering with a medical-grade battery company that makes implantable microbatteries for things like pacemakers, to design something safe to wear. Previously, we were using magnetic inductive coupling, and that seemed fine when you were holding it up to your eye. But the moment you put it on your eye and started moving your head and darting your eye and looking around, we were losing that connection to the wireless field. It wasn’t as reliable as we needed it to be. And so we made a decision about a year and a half ago to switch over to battery power.

I recall you always wanted to get batteries on board?

Sinclair: We thought so. But we sped that path up, because we came to the conclusion that the other path was just not a good way to go.

Why doesn’t this version have the image sensor?

Sinclair: We’ve decided to leave out the imager, the camera, for right now; it’s not critical to the use cases that we’re looking at first.

But you had been working to develop applications for people with low vision. What happened to that?

Sinclair: We’ve been using mainly low-vision capabilities built into smartphones right now to take pictures of things and bring them up to your eye for zooming in and out; we’ll add in the imager and test those capabilities out next. It’s just about there, but it wasn’t necessary to get to this milestone, so we decided to simplify things a little bit.

Given the amount of lens real estate being taken up by batteries and chips, was oxygenation an issue?

Sinclair: Absolutely. That was a core engineering point that needed to be solved before we could get to this lens. So this lens has channels built into it and a special design that allows air to get in and get through. The oxygen diffuses out over the surface of the cornea and the sclera.

A transparent contact lens showing computer chips and circuitry within its periphery

The batteries and chips within the Mojo Lens are arranged to preserve peripheral vision.

Mojo Vision

Does the circuitry block vision at all?

Sinclair: See the cutout on the side? Imagine I’m wearing it. It’s going to be oriented like this [the cutout away from the nose] because I need the peripheral vision on the outside, not towards the nasal side. Ultimately, there’s even more we can do to push components further toward the edges of the lens to maximize light entering the pupil.

Now that you explain the arrangement of circuitry to protect peripheral vision, it seems obvious, but some of the most obvious things take figuring out.

Sinclair: It wasn’t immediately obvious; our original design had [the electronics] all the way around.

What happens next?

Sinclair: We’re already wearing lenses that don’t have any electronics in them, but they’re shaped the same way, so that we can test for comfort and for how long can we wear them and have the oxygenation still working to our satisfaction.

Next we start testing [the complete prototype] on-eye, and see just how well it works in different situations. We can’t say exactly when that happens. We hope it’s soon, but we’ve got to make sure it’s safe and everything’s working the way we expect it to work. That testing will start with Drew Perkins wearing it, our CEO, then probably Mike Wiemer, our CTO. And then it goes to folks like myself and others on the executive team, along with some of the key engineers that need to start evaluating things quickly.

We’ll be testing the software, the battery life, and the wireless connectivity and [its] speeds. There’s likely to be a spin of one, two, or three of the chips built into the lens as we discover things that don’t work right or could be optimized to work better together as a system.

What’s the timeline for commercialization?

Sinclair: Everything is predicated on eventually getting FDA certification. We don’t like to presume how long that’s going to take.

You’re going for the consumer market. Today, it seems, most AR glasses manufacturers have decided to focus on the enterprise market initially. Why the different path?

Sinclair: With AR glasses, there are definitely some awesome enterprise use cases. But these are not great for contact lenses. Say you’re an IT manager, and you’ve come up with an awesome contact lens application. Can you tell your workers to wear a contact lens? Not usually. But consumers can make that decision. The reason people wear contact lenses is very consumery: I want to look like myself. I want to use it when I’m working out or doing sports. I don’t like things on my face. I don’t like the fashion sense of glasses; it’s not me. We decided to lean into those reasons that people pick contact lenses.

Can you talk about pricing?

Sinclair: Like anything else, when we first bring it out, it’ll be a little expensive. Our goal when we’re running at volume is that it should come out somewhere close to a high-end smartphone. But factor in the fact that people are already spending US $500, $600, or $700 for eyewear today, subtract that out of the total price, and the adder on top of that is not huge.

This article appears in the June 2022 print issue as “My Peek Through Mojo Vision’s AR Contacts.”

The Conversation (1)
netanel frankel30 Jun, 2022
INDV

How fragile is this product and what is the life cycle of one. Will people really spend $500+ on something that can be easily lost or damaged.

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
Blue

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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