Acoustic droplet ejection was first reported in 1927 by Robert W. Wood and Alfred Loomis, who noted that when a high-power acoustic generator was immersed in an oil bath, a mound formed on the surface of the oil and, like a “miniature volcano,” ejected a continuous stream of droplets.
Acoustic ejection of tiny particles was first described by Robert W. Wood and Alfred Loomis in 1927. When a powerful acoustic device was submerged in an oil bath, it created a small hill on the surface, which then released a steady flow of tiny droplets, much like a miniature volcanic eruption.