First of all: It’s about the skin of mice. They, the mice, carry the newly developed sensor, which could give drug research against cancer a boost. Does a drug work in the test animals or not? Is the tumor getting smaller? It should now be possible to answer these questions much more quickly and easily, because the sensor delivers its data in real time.
Researchers like to use descriptive names for their inventions, as do the engineers at Georgia Institute of Technology and Stanford University. They named their new device “FAST”, which is an abbreviation for “Freadable Autonomous Sensor Measuring Tumors” (flexible autonomous sensor that measures tumours) and at the same time of course means “fast”. The sensor is not only fast, but according to its developers it is also extremely precise can recognize the device.
Cracks in the gold layer
This was made possible by an embedded layer of small gold circuits on the elastic, skin-like polymer strip. When the strip is stretched, small cracks form in the gold, which also increases the electrical resistance in the sensor. Conversely, when the stripe contracts, the material around the cracks comes into more contact again and conductivity improves. According to the study, the changes in conductivity can then be mathematically related to changes in the tumor volume.
One hurdle the researchers say they had to overcome was the fear that the sensor itself could interfere with the measurements because it might put pressure on the tumor, squeezing it, so to speak. To avoid this risk, the mechanical properties of the flexible material have been carefully tuned, making the sensor as pliable and supple as real skin.
The sensor strip is then in turn connected to a small battery-powered electronic “backpack”, a transmitter unit that forwards the data to a smartphone. According to the researchers, their invention offers several significant advances. Until now, tumor monitoring in mice has been very complicated and time-consuming, primarily because of the biological differences between tumors and the inadequacies of the measurement methods. “In some cases, the tumors to be examined have to be measured by hand with calipers,” says Alex Abramson, first author of the study. And radiological measurement methods could not be used continuously either, which means that real-time monitoring is ruled out.
Faster, cheaper screening?
With “FAST” everything is supposed to get better. According to its developers, the system offers several significant advances. First, it allows for continuous monitoring as the sensor is physically attached to the mouse and stays in place throughout the trial period. Second, the sensor is able to measure shape changes that would be difficult to detect with other methods. Third, the system is both autonomous and non-invasive, sticks to the skin like a band-aid, is battery operated and wirelessly connected, allowing the mice equipped with it to move freely. Finally, the FAST packs are reusable, only cost around $60, and can be attached to the mouse in minutes.
The sensor’s design appears very simple, says study leader Alex Abramson, but its “benefits should be of great interest to the pharmaceutical and oncology community. FAST could significantly speed up, automate and reduce costs the process of screening cancer therapies.”