The big challenge with brains is that the biomolecules in tangled neurons that we want to understand are too tiny and intertwined for study. The polymers in a diaper expand in contact with water.
Boyden's Big Idea is to put those two facts together. Why not insert such polymers into (dead) brain cells, get these polymers to hook onto the desired biomolecules, then douse them with water to get them to swell? As they swell, they pull apart and untangle the biomolecules. And voila! These biomolecules can be studied in detail.
Boyden's hope is that such studies will unveil insights about Alzheimer's, Parkinson's, and other neurological diseases. How cool is that?