This is the first example of a material that simultaneously possesses the three qualities of semiconductivity, intrinsic stretchability and full degradability. Other attempts resulted in semiconductors that either did not break down completely, or had reduced electrical performance when stretched.
Zhenan Bao has solved this problem – by combining a rubbery organic polymer with a semiconducting one.
Her team synthesized and mixed the two degradable polymers, which self-assembled into semiconducting nanofibers embedded in an elastic matrix. Thin films made of these fibers could be stretched to twice their normal length without cracking or compromising electrical performance. When placed in a weak acid, the new material degraded completely within 10 days. (Bao said that it would take much longer in the human body.) The semiconductor was non-toxic to human cells growing on the material in a petri dish.