Sound waves to chill ice cream
On April 15, 2004, Earth Day, Ben & Jerry's announced the development of an environmentally friendly thermoacoustic chilling prototype. Following a company-wide audit of Ben & Jerry's refrigeration uses and its impact on the environment, acousticians at Pennsylvania State University, in coordination with Ben & Jerry's and Unilever, developed the prototype. This prototype uses a "bellow bounce" resonator with high-amplitude sound waves in an inert gas - helium, which is converted into cooling power. According to Pennsylvania State University, the thermoacoustic refrigeration process has many advantages, in particular less maintenance, due to the elimination of mechanical equipment, and better temperature control. This new compact approach to thermoacoustic chillers is expected to be easily adopted for beverage vending machines and ice-cream sales cabinets, as well as for cooling microprocessor chips in computers. Although the main advantage of thermoacoustic chilling is being more environmentally friendly through the use of natural inert gases, many obstacles to its development remain, particularly cost.