Cheap & Flexible Ultrasound Transducers

Ultrasound equipment can be quite expensive, and those costs are often passed along to the patient. When my child was born two years ago, a single ultrasound session cost us over a thousand dollars! But thanks to engineers at the University of British Columbia, equipment costs may be drastically lower in the near future, costing as little as $100 for an ultrasound scanner. The innovation is a new type of ultrasound transducer only several inches across that can be powered by a smartphone.

Conventional ultrasound device.

To get images from inside the body, called sonograms, normal scanners use piezoelectric crystals. These crystals have been replaced in the new device by polymer capacitive micro-machined ultrasound transducers, called polyCMUTs. These are tiny, vibrating, drum-like structures made from a polymer resin, and they are much cheaper to manufacture, according to research published recently in Nature Microsystems & Nanoengineering.

Silicon materials, with which transducers are usually made, can be quite costly to make, requiring expensive labs with advanced environmental controls. Needing much less in the way of equipment and regulated manufacturing environments, the polyCMUTs can be made for much cheaper and with significantly fewer steps. They can also be powered by a smartphone, since the device runs on only 10 volts. This makes it quite suitable for use in remote areas or in emergencies when normal power supplies are interrupted.

In addition, the technology can produce sonograms that are as good or better than those made by piezoelectric transducers, in terms of detail. Another advantage is the flexibility of polyCMUTs, which could be built into fabric wraps that could be wearable, unlike the rigid silicon transducers. A wearable device would make it easier for medical workers to perform ultrasound scans, as well as providing a more detailed view of internal structures.

The engineers are now busy developing prototypes for clinical applications. They hope to further miniaturize the transducers in the near future. Plans include using the device to peer inside of veins and arteries, and developing clothing that could monitor your heartbeat. I couldn't get hold of any open source pics of the new device, but you can see what it looks like in the following video.