Appendix A. Acoustic Droplet Ejection Technology; Ade History - Labcyte Echo 520 User Manual

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P P E N D I X
A D E
COUSTIC ROPLET JECTION
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ECHNOLOGY
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ADE history

Simple ADE (Acoustic Droplet Ejection)—liquid transfer using acoustic
energy—dates back to early experiments with high-intensity acoustic
beams at the Tuxedo Park laboratory of Alfred Lee Loomis in 1927. It was
observed that immersing a high-power acoustic generator in an oil bath
would create a mound at the surface "erupting oil droplets like a miniature
volcano."
Improvements in the 1950s and early 1960s localized the energy with
"exponential" acoustic horns or focused it with acoustic lenses, but still
maintained the high intensity of earlier devices. These devices created drops
with a continuous application of acoustic energy to form geysers of small
droplets or patterns of disturbances on the liquid surface where some of
the swells grew large enough to pinch off and become drops.
The introduction of a lower-intensity process that both focused and pulsed
the acoustic energy to create a single "drop-on-demand" was developed in
the early 1970s. Drop-on-demand technology has been extended to create
today's "ink jet" printing.
The increasingly automated nature of life science research during the
1990s, with its need for precise and reliable robotic liquid dispensing, led to
the application of focused-acoustic, drop-on-demand technology to life
science liquid handling in the 2000s.
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