Put your hand on your heart. Can you feel it beating? There are people whose heart does not function well and therefore can die any moment. They often have to wait for a long time for a transplant heart. I want to do something about that. Imagine we could 3D print a beating heart. Then, we wouldn’t have to wait for such a long time for transplant hearts. What do we need to make such a heart? A biomaterial that moves like our heart muscle. I am developing a movable biomaterials that shrink and expand like a heart: a responsive biomaterial. With molecules that respond to light, temperature or water, we can make these materials move. And if we succeed with that beating material, we can 3D-print a heart. Hopefully, in the future we can save heart patients with the help of a beating biomaterial.