A door sensor uses crushed garlic peel and plastic to generate an electrical signal as the door opens. When the layers touch and separate, static electricity is produced. A two-sided garlic-peel version generated about 400 volts at very low current.

Researchers Deepak Bharti and Manas Tiwari at Malaviya National Institute of Technology Jaipur demonstrated a home-security system that alerts a smartphone when the door opens, detecting openings with 92% accuracy across 50 tests. The sensing element needs no external power, although the microcontroller transmitting the alert used a power bank.