Bubble machines use a thick glycerin-based soap solution (bubble juice) and a series of plastic wands to generate hundreds of floating soap bubbles. There is no advanced technology behind the bubble production--the wands are mechanically dipped into the soapy solution and bubbles are formed in the open air. A small electric fan may encourage bubbles to move away from the machine, but that's as high tech as it gets.
Bubble machines have been available for decades, primarily as gimmicks for show bands or attention-seeking shop owners. Perhaps the most famous use of bubble machines occurred weekly on the American television program The Lawrence Welk Show. Welk's sophisticated arrangements of popular hit songs was often called 'Champagne music', so Welk used bubble machines to suggest the bubbles found in champagne.
Modern DJs have rediscovered the appeal of bubble machines, although their use is usually limited for safety reasons. Party goers tend to associate free-floating bubbles with happier memories of childhood, so DJs will occasionally generate a few hundred bubbles for atmosphere. Hosts of Halloween parties may also use smaller bubble machines and dry ice fog machines to create an eerie backdrop.
Commercial bubble machines can cost as much as $200 USD or more. Much of this expense comes from lighting effects and remote control units. Less elaborate models for home use can be found online or in party supply stores for under $30 USD. The soapy solution can be ordered in gallon jugs, although users can also fill the reservoir with ordinary toy bubble solutions or homemade formulas involving dish detergent and glycerin. Some specialty stores even offer bubble solutions which glow in the dark under black light conditions.
Another form of bubble machines can occasionally be found outside small retail shops. Because soap bubbles create attention, store owners may mount a battery-powered animated toy which blows bubbles. The character has an articulated arm which dips the plastic bubble wand into a container of solution and then draws it to a small blower hidden in its mouth. The combination of an animated toy and bubbles almost certainly attracts those passing by.