Oncle Sam is a popcorn machine art installation which focuses on popping corn one kernel at a time, allowing the user to partake of a tasty snack without consuming too many calories.
The leisurely popcorn machine utilizes a tea-light candle to heat a single grain of corn. Once duly popped, salt is also added for flavor. Each step of the process is performed with low-tech levers and pulleys, and produces just one finished popcorn at a time, perhaps increasing the appreciation of flavor as a result.

Oncle Sam was created by Ecole cantonale d'art de Lausanne (ECAL) students Laurent Beirnaert, Pierre Bouvier, and Paul Tubiana for ECAL’s Low-Tech Factory exposition – the same project which was home to the Rocking-Knit Chair.
This short promo video demonstrates Oncle Sam popping corn.
Source: ECAL, via designboom