Light-activated heart cells help guide robotic stingray
Engineering feat could pave way for new artificial organs
![robotic stingray](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2016/07/070716_mr_stingray-bot-main_free.jpg?fit=860%2C460&ssl=1)
SEE-THROUGH STINGRAY A tiny robotic stingray with silicone skin and a gold skeleton uses muscles made out of rat heart cells to wiggle its fins.
Karaghen Hudson and Michael Rosnach