A typical ultrasound scanners utilizes piezoelectric crystals. These are used to generate images of the inside of the human body, which are then transmitted to a computer where the images are converted into sonograms (a visual representation of the spectrum of frequencies of sound). With the new innovation, the technologists did not use piezoelectric crystals and instead replaced these with tiny ‘vibrating drums’ formed from a polymer resin. The resin used was polyCMUTs (polymer capacitive micro-machined ultrasound transducers), EE News reports. These resins can be produced at a lower cost.
Speaking with Phys.Org, lead researcher Carlos Gerardo said why the new material had been selected: “Transducer drums have typically been made out of rigid silicon materials that require costly, environment-controlled manufacturing processes, and this has hampered their use in ultrasound.”
He adds: “By using polymer resin, we were able to produce polyCMUTs in fewer fabrication steps, using a minimum amount of equipment, resulting in significant cost savings.”
In tests using the new approach, the sonograms were assessed as equally sharp and detailed as sonograms generated by conventional piezoelectric transducers. The sonograms generated with the new system required only 10 volts, meaning that the equipment can be powered simply by using a smartphone.
Using the prototype, the researchers aim to issue a patent and then develop devices suitable for medical use. It is hoped that if the technology can be miniaturized then new insights with ultrasound could be produced, such as examining inside arteries and veins.
The new device has been described in the journal Microsystems & Nanoengineering. The associated research paper is titled “Fabrication and testing of polymer-based capacitive micromachined ultrasound transducers for medical imaging.”