Heart failure has long been treated as a problem of chemistry, electricity and plumbing: drugs reduce the strain on the heart, implanted devices regulate its rhythm, and mechanical pumps can take over part of its workload. A new review in Nature Communications argues that another approach deserves serious attention—soft robotic cardiac sleeves designed to wrap around the heart and help it contract. These flexible systems are being developed as a gentler alternative to rigid mechanical support, but the path from laboratory prototype to routine clinical treatment remains technically demanding.

The concept is deceptively simple. A soft robotic sleeve is positioned around the surface of the heart and uses compliant actuators to reproduce or assist the squeezing motion of cardiac muscle. Instead of forcing blood through the body with a rotating impeller, as ventricular assist devices do, the sleeve aims to support the heart’s own pumping action from the outside. Depending on the design, its artificial muscles may be driven by pneumatic pressure, hydraulic fluid, cables, shape-changing materials or other mechanisms that generate controlled contraction.

That softness is central to the technology’s appeal. The human heart changes shape continuously as it fills and ejects blood, while its surface is delicate, wet and constantly moving. A rigid device can impose damaging pressure or interfere with natural motion. Soft robots, by contrast, can conform to curved biological structures and distribute forces over a larger area. In principle, a cardiac sleeve could provide assistance without placing a rotating pump inside the bloodstream, potentially reducing complications associated with blood-contacting components such as clot formation and bleeding.

The review by Foroughi, Nazari, Lovell and colleagues examines why that promise has not yet translated into widespread clinical use. One of the hardest engineering problems is synchronisation. The device must respond to the heart’s electrical and mechanical activity with precise timing, assisting contraction without obstructing relaxation or filling. If the sleeve squeezes too early, too late or too forcefully, it could reduce cardiac output rather than improve it. Reliable sensing systems will therefore be needed to detect the heart’s phase of activity and adjust assistance beat by beat.

The heart is also not a uniform pump. Its ventricles, atria and great vessels have different shapes and roles, and the geometry of a failing heart can vary substantially from one patient to another. A sleeve designed around a healthy anatomical model may fit poorly on a dilated or scarred heart. Uneven contact could create concentrated stresses, restrict coronary blood flow or injure surrounding tissue. The review highlights the importance of patient-specific designs, adaptable structures and carefully controlled force transmission if these devices are to work safely across diverse forms of heart failure.

Power and control present another obstacle. Pneumatic and hydraulic systems can generate strong, smooth actuation, but they may require external pumps, tubing and reservoirs that limit mobility and complicate implantation. Electrical systems can be more compact, yet they introduce questions about heat, battery life, insulation and long-term reliability. Every connector, sensor and moving component adds a potential failure point. A clinically useful sleeve must operate continuously for months or years, not merely survive short laboratory demonstrations.

Biocompatibility and surgical practicality are equally important. Any implant placed around the heart must resist inflammation, infection and tissue adhesion while remaining mechanically stable. Surgeons would need to position it without damaging the myocardium, coronary vessels or nearby organs. The device must also be removable or adjustable if a patient’s condition changes. Materials that perform well in benchtop tests may behave differently inside the body, where they encounter body fluids, immune responses, repeated mechanical loading and limited space.

The paper places these engineering questions within the wider challenge of clinical translation. Demonstrating that a sleeve can make a model heart beat more effectively is only an early milestone. Researchers must establish safety, durability and meaningful improvements in circulation through carefully designed animal studies and human trials. They will also need to define which patients are most likely to benefit: people awaiting transplantation, patients recovering from temporary cardiac injury, or those with chronic heart failure who are not candidates for conventional mechanical pumps. Regulatory approval will depend on evidence that benefits outweigh surgical and device-related risks.

Soft robotic cardiac sleeves therefore occupy an intriguing middle ground between biological repair and mechanical replacement. They do not attempt to rebuild damaged heart muscle, but they may provide external assistance while preserving more of the organ’s natural function. The review suggests that progress will depend on collaboration among roboticists, cardiologists, surgeons, materials scientists and rehabilitation specialists. If designers can solve synchronisation, anatomical fit, power delivery and long-term safety, an external robotic muscle could eventually become a new tool against heart failure. For now, however, the technology remains a compelling research frontier rather than a ready-made clinical cure.

Subject of Research: Soft robotic cardiac sleeves for assisting heart function in heart failure.

Article Title: Clinical translation and engineering challenges of soft robotic cardiac sleeves for heart failure.

Article References: Foroughi, J., Nazari, H., Lovell, N. et al. “Clinical translation and engineering challenges of soft robotic cardiac sleeves for heart failure.” Nature Communications 17, 8254 (2026). https://doi.org/10.1038/s41467-026-76596-z

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41467-026-76596-z

Keywords: soft robotics, cardiac sleeves, heart failure, cardiac assist devices, biomedical engineering, medical robotics, mechanical circulatory support, clinical translation

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