Engineers at UNSW Sydney have built a soft robotic heart that beats like a real one and can reproduce specific cardiac diseases. Made of silicone and hydraulic "muscles," the device is meant to give researchers a realistic environment for testing catheters and medical devices before they reach animals or patients. The work was reported on 28 July 2026 via UNSW and published in Nature Communications and Advanced Science.
Key takeaways
- A UNSW Sydney team built a soft robotic model of the left side of the heart
- Construction: silicone membranes, hydraulic artificial muscles, artificial papillary muscles and chordae tendineae
- The model reproduces mitral valve prolapse and regurgitation, plus heart failure with preserved ejection fraction (HFpEF)
- It was used to test new soft robotic cardiac catheters and ultrasound imaging compatibility
- The research was published in Nature Communications and Advanced Science
A heart you can make sick on demand
The point of the project is not the beating itself but that the device can simulate disease. The model reproduces the layered architecture of heart muscle using soft, hydraulic muscle fibers wrapped around silicone chambers — so it recreates not only a healthy rhythm but also pathologies.
We found a way to model this muscle fibre architecture using soft robotic artificial muscle fibres.
Dr James Davies, postdoctoral researcher at UNSW Medical Robotics Lab.
The team demonstrated two common pathologies. The first is mitral valve prolapse and regurgitation — blood leaking backward. The second is HFpEF?HFpEF — heart failure with preserved ejection fraction: A form of heart failure in which the heart contracts normally but relaxes and refills poorly between beats., a condition in which the heart relaxes poorly between beats. The model also reproduces altered blood pressures and flows, not just wall motion.
What it is made of
The build combines several layers. Silicone membranes form the internal chambers, and around them sit soft robotic artificial muscles driven by hydraulic pressure, mimicking the layers of natural muscle.
It also adds artificial papillary muscles and chordae tendineae?Chordae tendineae: Thin cords connecting the heart-valve leaflets to the papillary muscles, keeping the valves under tension. — the structures that hold and tension the valves in a real heart. For now the model reproduces only the left side of the heart and is described as a proof-of-concept?Proof-of-concept: An early prototype that proves an idea works, but is not yet a finished product. requiring further clinical validation. This is a research tool, not an implant or a medical product.
A testbed, not a prosthesis
The goal is different from an artificial heart implanted in patients: it is a testing platform. On the model, the team tested new soft robotic cardiac catheters, blood pressure and flow measurements, and compatibility with echocardiography?Echocardiography: Ultrasound imaging of the heart, showing its structure and motion in real time.. Devices can be navigated inside the beating cardiac structures and observed in action.
That sets the UNSW approach apart from classic simulators — rigid models or purely computational flow simulations. A physical, soft model provides mechanical contact and realistic tissue response that numerical simulation alone cannot. The team notes the model helped reduce animal testing in the early stages.
The project was led by Professor Thanh Nho Do of the UNSW School of Biomedical Engineering, working with cardiologists including Professor Christopher Hayward of St Vincent's Hospital Sydney — a signal that the tool is built with real clinical use in mind.
Why it matters
Soft robotics is usually associated with grippers and manipulation. This project shows a less obvious value: building realistic biological "phantoms." Testing cardiac devices is expensive, slow and ethically fraught, because it relies on animals and late-stage clinical trials.
A physical model that beats and can reproduce a specific disease shortens that path. For medical-device makers, that is potentially a cheaper and faster development cycle. More broadly, it is an example of robotics and medicine converging, where the same techniques (soft actuators, pressure control, artificial tissue) serve not factory work but understanding and treating the human body.
What's next?
- The team plans patient-specific models built from medical imaging data
- The next step is clinical validation — the current model is a proof-of-concept, not a validated diagnostic tool
- Open questions include extending the model beyond the left side of the heart and integrating it with tests of new robotic catheters
Sources
- Robohub — Soft robotic heart offers new way to study disease and test life-saving devices
- Nature Communications — Soft robotic heart model
