Pittsburgh, PA, US
Luka Pocivavsek, Joseph Pugar, Antonio Torres
A nature-inspired surface design platform that uses reversible surface topography (i.e. wrinkles) to renew and self-clean.
Aruga is currently being applied as a vascular implant technology. Additionally, Aruga is investigating the platform potential of the technology to identify if mimicking this phenomenon in industrial synthetic surfaces decreases fouling and results in an optimized surface. From sustainable architecture to other algae and water technologies, Aruga surfaces can add an element of sustainability that current solutions, such as complex chemical coatings and time-intensive and expensive cleaning protocols, do not provide.
1. What is the problem you’re trying to solve and how does your design help?
Cardiovascular disease caused by blocked arteries is the primary cause of morbidity and mortality in the western world. Surgical interventions, in the form of bypass surgeries, are among the mainstay therapies of blocked arteries. Currently, surgeons primarily use a piece of native artery or vein to construct a new conduit for blood flow when performing a bypass operation. However, the performance of these grafts degrades significantly as the bypassed arteries become smaller. In fact, in the areas where the need for bypass operations is the highest, heart and lower extremity, artificial grafts are rarely used because of dismal outcomes. There is a need for a new generation of artificial vascular grafts that rely on new bio-inspired technologies that can be used in coronary artery bypass (CABG) and peripheral revascularization.
Aruga’s graft surfaces mimic how human arteries use dynamic wrinkling patterns to physically keep platelets from binding to the artery surface as blood flows through the vessel. This design does not require any additional driving force – as our hearts beat, and as the pressure in our cardiovascular system goes transitions between diastolic and systolic pressures, the surface wrinkles come and go. In other words, the implanted our device surfaces wipe themselves clean of depositing platelets every time the patient’s heart beats.
2. What makes your design different than previous or current approaches to the problem you’re trying to solve? What are the social, cultural, and/or environmental wins that your innovation provides?
Self-cleaning surfaces, e.g. anti-fouling and more specifically anti-thrombotic solutions, is a growing market. Typically, solutions rely on either chemically complex and environmentally harmful or capital-intensive manual solutions that, in the context of vascular medical devices, still result in poor patient outcomes. Our solution is unique because it is a purely geometric and physical design change to surface modification and is synergistic with presently adopted solutions such as anti-fouling coatings. Our technology is also tunable and can be optimized to keep a vast array of foulants from depositing on the surface. It is a nature-inspired surface design platform.
3. How did you apply lessons from living organisms to your design and what difference did that make?
Wrinkled surface patterns present themselves in nature often. Specifically, we look at how mussel byssuses, dolphin skin, and human arteries, for example, use changing wrinkling patterns to optimize their surfaces and remain deposit-free. What we have labeled as “dynamic surface topography” is a natural cleaning mechanism nature uses to physically prohibit debris from adhering to a surface. As surface wrinkles come and go, foulants are continuously ejected and the surface continuously renews.