Boex
http://www.boex.co.uk/category/exhibition

These two designers based in Cornwall have done some really lovely, sensitve and stimulating spaces.

Playful, Educational Spaces-

Royal Cornwall Museum Exhibition

Have also done designs for a dementia ward
http://www.boex.co.uk/projects/dementia-ward#

There are also some interesting examples at places I have visited recently -

Braford Film Museum
Manchester Museum