Researchers at Drexel University have announced an innovative alternative to surgery for children with congenital heart disease. The new blue-light-activated shunt is able to expand as the child grows, eliminating the need for additional invasive interventions. Children born with defects affecting the lower chambers of the heart often require multiple surgeries early in life. The first procedure usually involves the placement of a shunt to improve blood flow. However, as the child grows, it must be replaced with a larger one. And that comes with high risks. The new shunt is based on sensitive hydrogels that can expand when exposed to light. The researchers chose blue - as a safe trigger to activate the response. In lab tests, the team was able to increase the diameter of the shunt by 40%, which is the same size as the large units used for pediatric heart surgery. To activate the device, surgeons insert a fiber-optic catheter into the artery, avoiding open surgery. This allows the size of the shunt to be precisely adjusted to each patient's needs. In the future, the scientists intend to test full-size prototypes of the shunt in a simulated setup that replicates the human circulatory system. If these tests prove successful, the researchers plan to move on to animal experiments.