Next time you stop at the drive-thru on the way home, place your food in the microwave (but don't turn it on), and it will stay nice and warm until you're ready to eat. Microwaves are small ...

Ayaka Ueda, 41, developed a bag called Willcook that uses electricity to raise the temperature inside of it to heat food and keep it warm. Willcook is about the size of a standard sheet of paper.