Newswise — A key part of a medical ultrasound scanner is the transducer probe used to convert sound waves to electrical signals and vice versa. Traditionally, such transducers are made from piezoelectric materials, which produce a voltage when stressed and which deform when an external voltage is applied to them.

But better transducers can be made using the principle of the condenser microphone--something with a back plane and a thin membrane that vibrates. To compete with

traditional piezoelectric ultrasound transducers, though, capacitive transducers must contain enormous electric fields. This has been hard to accomplish in the past, but researchers have made considerable progress using many of the same techniques that are applied to the fabrication of microelectronic devices. Soon you can expect to see capacitive transducers being sold routinely with medical ultrasound equipment, which should make the images produced become even more sharp than they are today.