Flexible sensors can measure changes in subcutaneous tumors

Engineers at Stanford University and the Georgia Institute of Technology in the United States have invented a small autonomous device with a stretchable flexible sensor that can be attached to the skin to measure changes in the size of tumors below. This battery powered non-invasive device has a signal sensitivity of 10 microns and can wirelessly transmit results to smartphone applications in real-time at the touch of a button.




Researchers say this "Flexible Autonomous Sensor for Measuring Tumor" (FAST) represents a new, fast, inexpensive, portable, and accurate method for testing the efficacy of anticancer drugs. In the long run, it may indicate a new direction for cancer treatment. FAST sensors can detect changes in tumor size on a minute scale, while caliper and bioluminescence measurements typically require several weeks of observation to detect changes in tumor size.




FAST consists of a flexible and stretchable skin like polymer that includes a layer of embedded gold circuitry. This sensor is connected to a small electronic backpack. The device measures the tension (the degree of stretching or contraction) on the membrane and transmits the data to the smartphone. Using the FAST backpack, the potential efficacy associated with tumor size regression can be quickly and accurately determined, or quickly tracked for further research.




Researchers say there are at least three significant advances in the new device. First, it provides continuous monitoring because the sensor is physically connected to the mouse and remains in place throughout the experiment; Secondly, the flexible sensor wraps around the tumor, enabling it to measure shape changes that are difficult to distinguish using other methods; Thirdly, FAST is both autonomous and non invasive. It is connected to the skin, similar to band-aids, battery operated, and wireless connections. The mouse can move freely without being obstructed by devices or wires, and scientists do not need to actively operate the mouse after placing the sensor. FAST backpacks can also be reused, with an assembly cost of around $60, and can be connected to a mouse in a few minutes.




"This is a seemingly simple design," said Alex Abramson, the first author of the study, a postdoctoral fellow at the Stanford Institute of Engineering's Baugnan Laboratory, and currently an assistant professor at the Georgia Institute of Technology. "But the pharmaceutical and oncology communities should be particularly interested in these advantages. FAST is automated, which can significantly accelerate the speed and reduce the cost of the cancer treatment screening process."