Their inventions are changing lives of the people across India.
Mitticool turned out to be a hit - its maintenance costs were minimal, and the fact that it ran without electricity was a boon for villages where power was in short supply.
There is a growing trend of frugal innovation in India.
Mitticool, a clay refrigerator that works without electricity had turned the world's attention to its creator Mansukhbhai Prajapati, a craftsman based in Gujarat.