Look for a real problem that affects society and design a digital manufactured thingy to eliminate it! Have you tried to slice vegetables with broken arms, or parked in torrential rain at night, so that you can't clearly see the paddle? Make life barrier free and more accessible.
For your inspiration check out a project made by Anna Borbála Lányi:
PLAY bALL is a skill development ball game designed for every children, regardless of their ability or disability. The flat-packed, laser-cut made object elements enhance the experience of playing, which can motivate children and facilitate the work of teachers.