randomErr writes: 5.7 million adults in the United States have heart failure each year with about 41 million worldwide. Currently, treatment involves surgically implanting a mechanical pump, called a ventricular assist device (VAD), into the heart. The VAD helps maintains the heart's function. But patients with VADs are at high risk for getting blood clots and having a stroke. Researchers at Harvard University and Boston Children's Hospital have created a soft robotic sleeve that doesn't have to be implanted. The robotic sleeve slips around the outside of the heart, squeezing it in sync with the natural rhythm. "This work represents an exciting proof of concept result for this soft robot, demonstrating that it can safely interact with soft tissue and lead to improvements in cardiac function," Conor Walsh, said in a press statement. Seeker reports: "The sleeve they developed is made from thin silicone and attaches to the outside of the heart with a combination of suction devices and sutures. It relies on soft, air-powered actuators that twist and compress in a way that's similar to the outer layer of muscle of a human heart. A gel coating reduces any friction between the sleeve and the organ. Because the sleeve is soft and flexible, it can be customized to fit not just the size and shape of individual hearts, but augment the organ's weaknesses. For example, if a patient's heart is weaker on the left side than the right, the sleeve can be tuned to squeeze with more authority on the left side. As the organ gains strength, the device can be adjusted." The study has been published in the journal Science Translational Medicine.