Artificial prosthetic hearts have typically been built using conventional electromechanical components that first saw use in non-medical liquid pumping applications. While beneficial for many patients, the technology remains quite limited in practice due to a host of issues. Now engineers at Cornell University have developed a totally new technology to create pneumatic devices and used it to build a pump resembling a human heart.
Their method relies on a soft material that feels like memory foam. The stretchable material starts as liquid and is poured into a mold designed to create channels throughout that guide liquid to pass between different chambers and components. The entire device expands and contracts along with the changing pressure of the liquid passing through. It generates pressures higher than any previous soft pumps and works at frequencies close to our natural heartbeats.
Some details from Cornell:
The porous channels are made by mixing salt with the rubbery elastomer when it’s still a liquid. Once the elastomer cures and hardens, the salt is removed. To seal an organ or prosthetic so air or fluid can be pumped through it without escaping, Shepherd and colleagues coat the outside with the same polymer but without the salt.
The researchers used carbon fiber and silicone on the outside to fashion a structure that expands at different rates on the surface – to make a spherical shape into an egg shape, for example, that would hold its form when inflated.
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