Today’s brain interfaces that sense electrical activity and deliver chemical compounds tend to be rigid devices based on microneedles that can’t penetrate very deep without destroying tissue on the way. The needles are hard and so can only work on the outside periphery of the brain. Researchers at Toyohashi University of Technology in Japan have taken an interesting approach to overcome this problem by creating very thin needles that can behave as rigid when entering tissue but become soft once inside, allowing them penetrate deeper without causing much damage.
The technique works by embedding the microneedles within a block of silk fibroin, a biocompatible material used in medical applications. As pressure is applied to the block it dissolves, while the needle is pushed into the tissue below. This process continues as the block continues to dissolve with the needle moving deeper and deeper. This allows a very thin and long needle to be pushed into tissue without causing it any damage.
Study in Advanced Healthcare Materials: Dissolvable Base Scaffolds Allow Tissue Penetration of High-Aspect-Ratio Flexible Microneedles…