Scientists in Germany have succeeded in developing the smallest ultrasound detector ever created, which is tinier than a blood cell and opens up new possibilities in what is known as super-resolution imaging. The researchers describe the results as “breathtaking,” and hope the technology could allow for the study of biological tissue in unprecedented detail.
Developed by scientists at the Helmholtz Zentrum München (German Research Center for Environmental Health) and the Technical University of Munich, the new device represents something of a departure from the technology behind traditional ultrasound imaging, which usually relies on what are known as piezoelectric devices that take the pressure created by ultrasound waves and turn it into an electric voltage.
The image quality produced through this method is directly tied to the size of the piezoelectric detector, with the smaller the detector the higher the resolution, but this in turn compromises the sensitivity of the device. The authors of the new study detail a solution to this problem, by turning to a different type of imaging technology that relies on silicon photonics.
Silicon photonics technology has great potential in areas such as next-gen computing and data transmission, by allowing for miniaturized optical components to be assembled atop small silicon chips. The silicon is able to confine the light into very small dimensions, a capability the scientists were able to leverage for their groundbreaking device.
Called the silicon waveguide-etalon detector, or SWED, the device works by picking up changes in light intensity as they propagate through the miniaturized photonic circuits, instead of tracking voltage via piezoelectric crystals. The device is smaller than a blood cell and marks the first time a detector of that size has been used to detect ultrasound, according to the team.
“The degree to which we were we able to miniaturize the new detector while retaining high sensitivity due to the use of silicon photonics was breathtaking,” says Professor Vasilis Ntziachristos from the Technical University of Munich, lead of the research team.
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 approach to super-resolution imaging, as it’s known, could be applied to cells and tissues 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 detector was originally developed to propel the performance of optoacoustic imaging, which is a major focus of our research at Helmholtz Zentrum München and TUM,” says Ntziachristos. “However, we now foresee applications in a broader field of sensing and imaging.”
The research was published in the journal Nature.
Source: Helmholtz Zentrum München
