Popping Sound

It’s a nightmare for bubble blowers – the moment when, instead of leaving a bubble wand, a wobbling nearly-bubble seems to change its mind and deflate – hurtling back towards a terrified face and a soapy pop. This unfortunate quirk of surface tension is reversed here, inflating droplets of a soapy substance using ultrasound, as a step towards transforming drug delivery. Acoustic vibrations cause the edge of the droplet to buckle and rise (top row). Resonating vibrations grow the bubble, and a split second later it floats away (bottom right). Adapting the technique for industry, ultrasound could be used to create pharmacological foams – increasingly used over creams to deliver topical drugs onto skin when treating conditions like dermatitis and psoriasis.

Written by John Ankers

John Ankers

Writer

A former researcher in systems biology, John is now an online biology tutor and professional coach supporting the wellbeing of scientists and NHS professionals. He's writing, too, of course.

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• Image adapted from work by Duyang Zang and colleagues
• Functional Soft Matter & Materials Group, Key Laboratory of Space Applied Physics and Chemistry of the Ministry of Education, School of Science, Northwestern Polytechnical University, Xi’an, China
• Image originally published under a Creative Commons Licence (BY 4.0)
• Published in Nature Communications, September 2018