An unconventional, new ultrasound detector – smaller than a red blood cell – has been developed by scientists at the German Research Center for Environmental Health (HMGU) and the Technical University of Munich (TUM). The groundbreaking device can capture minute details with astounding clarity, which the scientists hope to leverage to study biological tissue.

The ultrasound detector or the silicon waveguide-etalon detector (SWED) works by picking up changes in light intensity as they propagate through the miniaturised silicon photonic circuits and is turned into electric voltage, instead of traditional ultrasound imaging techniques which rely on piezoelectric crystals to do the same.

The SWED device is around half a micron in size and at least 10,000 times smaller than the smallest piezoelectric detectors in clinical use, giving it the ability to image features smaller than one micrometer in size. This is called super-resolution imaging – the approach could not only be used to open up new possibilities in biomedical research and clinical diagnostics, but could also allow ultrasonic waves to be studied in ways not possible before.

“The degree to which we were we able to miniaturise the new detector while retaining high sensitivity due to the use of silicon photonics was breathtaking,” said TUM’s Professor Vasilis Ntziachristos. “The detector was originally developed to propel the performance of optoacoustic imaging, which is a major focus of our research at HMGU and TUM. However, we now foresee applications in a broader field of sensing and imaging.”