Digital lollipop

A digital lollipop is an electronic device that synthesizes virtual tastes by stimulating the human tongue with electric currents. The device can produce four primary tastes: sweet, sour, salty, and bitter. Digital lollipops were developed through research led by Nimesha Ranasinghe at the National University of Singapore.

Design
According to Ranasinghe, "The system can manipulate the properties of electric currents (magnitude, frequency, and polarity: inverse current) to formulate different stimuli. Currently, we are conducting experiments to analyze regional differences of the human tongue for electrical stimulation."

The devices generate alternating current signals through a sliver electrode, stimulating the tongue's taste receptors to emulate the major taste components. It also produces small, varying amounts of heat to simulate food.

Eventually, the digital lollipop could aid Alzheimer's patients by helping them "either enhance or suppress certain senses". It may also allow people with diabetes to experience sweetness without increasing their blood sugar levels. The National University of Singapore research team is developing Taste Over Internet Protocol (TOIP) that would allow taste information to be communicated between locations.