How the world’s first fully powered prosthetic leg could revolutionize powered prosthetics

Please can you introduce yourself and tell us about your role at Adaract?

My name is Marcus D’Ambrosio and I’m one of the co-founders and Chief Operating Officer at Adaract. I handle almost all of our business development and operations and will lead the software development of our prosthetic’s control system. One of my partners and the original founder of Adaract, Joseph Hill, will be answering some of these questions with me. Joe is the engineer and machinist behind almost everything we’ve created to date.

Adaract is an innovative company specializing in the development of a revolutionary new type of hydraulically-powered artificial muscle. Can you tell us more about the history of Adaract as well as what your mission is as a company?

Adaract has been a project-in-progress since 2020 for the original founder, Joseph Hill. Joe worked on our core technology as a passion project turned engineering capstone project for quite some time. It wasn’t until 2022 that the full founding team was built, and the company was completely incorporated and functioning full time.

Adaract’s mission is to enhance the mobility of man and machine with our artificial muscle technology. More specifically, we’ve built an incredible power system (the artificial muscle) that we believe can bridge a technology gap in powered prosthetics, powered orthotics, exoskeletons, and mobile robotics. Our long-term goal is to explore our core tech’s implementation in each of these industries to create better solutions for those with physical disabilities.

Please can you tell us more about the synthetic muscles you have created and how they can work in powering a prosthetic leg?

Adaract’s synthetic/artificial muscle is a hydraulically powered, variable recruitment actuator. Each muscle “fiber” can be activated individually, allowing incredible adaptability and power efficiency. The way that these muscles contract is by pumping a pressurized fluid into them, causing each fiber to expand radially and contract axially. This type of contraction, coupled with an appropriate linkage system, allows the muscles to provide our device with a full range of motion in both the knee and ankle joints with approximately 250 lb-ft of joint torque – this is about twice the torque of a Toyota Corolla.

Adaract’s Atalanta will be the world’s first fully powered prosthetic leg. What is distinctive about this technology compared to existing lower-limb prosthetics?

Almost all current lower-limb prosthetics are unpowered, with few exceptions. Compared to every unpowered device, our main advantage is the ability to provide substantial propulsive and supportive power to the joints. This should significantly reduce pain and fatigue and improve mobility in above-knee amputees.

Relative to other powered devices, ours will provide much higher power outputs, improved battery life, and improved durability while reducing weight and noise. Another key advantage is the affordability, as any other powered device or extremely durable microprocessor knee will cost at least three times as much as ours.

Adaract's soft muscle actuators are powered hydraulically. Although similar actuators appear in research, Adaract has developed a uniquely efficient version of these actuators better suited for use in prosthetic devices. Can you tell us more about how this technology is beneficial in prosthetics?

Although many attempts at highly functional powered prosthetics have been made, no one has been able to simultaneously overcome the barriers of weight, strength, power, and energy efficiency. This technology is beneficial in prosthetics because it allows us to build a first-of-its-kind powered prosthetic that doesn’t have issues with weight, strength, sound, or battery life. It is the perfect combination of hydraulic actuator power density with electric actuator controllability and operating efficiency.

Until now, how have you tested the strength and speed of the artificial muscle, and how do you plan on testing the prosthetics in real-world settings?

We have tested and validated that the muscle can provide the performance required to accomplish the innovation we are envisioning. The muscle, as designed currently, can lift >3800 lbs vertically, provide 250 lb-ft torque around the prosthetic joints, and fully activate in only 90 ms; this is ~3 times faster than a human brain can command a human muscle to act.

How do you believe your advancements in these devices could benefit people with physical disabilities?

Our advancements in prosthetics are expected to significantly reduce pain/fatigue, improve mobility, and prevent long-term comorbidities associated with above-knee amputation. Above-knee amputees expend 45-300% more energy while walking than non-amputees due to lack of propulsive power from their amputated limb; we expect our device to compensate for a large portion of this lost energy, restoring amputees with the energy and ability they deserve.

Additionally, walking on inclines/declines, stairs, and running can be extremely challenging for above-knee amputees due to lack of power in the knee and ankle of their prosthetic. Our device can provide this power and give amputees the opportunity to reclaim their mobility. Other results of unpowered prosthesis are hip/back pain and long-term deterioration of the hip, back, and sound limb joints due to overburdening with shifted loads. We hope to decrease this pain and requirement for future medical care by lightening the loads shifted onto other parts of the body.  

As we haven’t deeply explored what our products can do for non-amputees with mobility impairments such as lower limb paralysis, we can’t accurately speak to the benefits there, other than the ability to walk again.

Looking ahead, how do you imagine advancements in artificial muscle technology will develop over the coming decade? Are you hopeful that Adaract could also one day bring this technology to powered orthotics and exoskeletons?

In the next decade, we believe that soft muscle actuators like ours will become the forefront of the prosthetic, orthotic, exoskeleton, and mobile robotics industries, with Adaract leading the charge. We see the performance of our artificial muscles revolutionizing mobility of all kinds, both for man and machine.

Yes, Adaract is planning to expand our core technology to powered orthotics and exoskeletons as soon as 2023.

What is next for Adaract? Are there any more exciting projects coming up?

Right now, Adaract is focused on continuing our fundraising efforts and completing our human-testable prototype within the next two months. We are incredibly excited to get our device hooked up to someone and experiencing what it can do.

Additionally, we are always trying to build industry relationships to aid in bringing our technology to commercialization. Our full focus is to ensure that those with physical disabilities can benefit from what we’ve built.

Where can readers find more information?

Readers can learn more on our website: https://adaract.com. We are about to start a newsletter/mailing list that can keep people updated on our progress, as well. Also, we encourage interested readers to reach out to us at any contact information provided on the website.

About the Interviewees

Marcus D’Ambrosio – COO: Marcus currently manages all business development, operations, and investor relations at Adaract. He is also working in conjunction with Joe to develop the earliest stages of the control system for Adaract’s prosthetic leg. Before Adaract, Marcus graduated as the Valedictorian-equivalent from the University of Utah’s College of Engineering with a dual B.S. in chemical engineering and applied mathematics. Marcus previously served as CTO of a small AgTech company, where he built ML solutions for beekeeping applications and gained valuable small business development, operational, and managerial skills.

Joseph Hill – CEO: Joe currently leads the product, engineering, and manufacturing at Adaract – Joe makes all of the tangible magic happen. He is the lead engineer on all design work as well as the oversight in any manufacturing processes. Joe has been working on what turned into Adaract for nearly 3 years. What began as a passion project turned into an engineering capstone project turned into a startup company. Joe graduated as the Valedictorian-equivalent from University of Nevada, Reno with a B.S. in mechanical engineering. After graduating, Joe gained valuable experience as a Manufacturing supervisor at Hamilton Company before focusing on Adaract full time.