As everyone who has painstakingly straightened their hair knows, water is the enemy. Hair carefully straightened by heat will bounce back into curls the minute it touches water. Why? Because hair has shape memory. Its material properties allow it to change shape in response to certain stimuli and return to its original shape in response to others.
What if other materials, especially textiles, had this type of shape memory? Imagine a T-shirt with cooling vents that opened when exposed to moisture and closed when dry, or one-size-fits-all clothing that stretches or shrinks to a person’s measurements.
Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a biocompatible material that can be 3D-printed into any shape and pre-programmed with reversible shape memory. The material is made using keratin, a fibrous protein found in hair, nails, and shells. The researchers extracted the keratin from