Mad enough to have a dog called Igor: , by Jim Benton (New York: Simon & Schuster, 2005)

Franny K. Stein is a mad scientist. She's also about nine. She makes lots of things, does lots of experiments and keeps her family both proud and terrified. But when she wins the school science fair with a time machine (so you can eat your cake and have it) her middle name is revealed as Kissypie and the whole school laughs, She travels back to the past (we see her making her bringing a teddy bear to life) and changes her name to Kaboom but when she goes into her own future, her teen self is not just mad, but evil., They fight but draw, and Frannt goes back to the past to change not her name, but her reaction to being laughed at. This turns out fine. But annoyingly she also goes home and tidy's up her room and I can't see the logic in that at all.

A lovely book, especially if you've ever thought of putting the wheel-turning properties of a hamster to mad purpose.