Ranasinghe and his team used an RGB colour sensor and a pH sensor to capture the colour and acidity of a freshly poured glass of lemonade. This data was sent to a special tumbler in another location that was filled with water. An electrode around the rim of the tumbler mimicked the sourness of the lemonade by stimulating the drinker’s taste buds with a pulse of electricity. LED lights replicated the colour.

Source: Virtual lemonade sends colour and taste to a glass of water | New Scientist