A team of scientists at Binghamton University in New York State have developed a technique that lets them salvage material from old CDs to make flexible biosensors that are inexpensive and relatively simple to produce. The method involves using a chemical process and sticky tape to peel off the metal coating from the disks, and then using a crafting cutter to shape the flexible material as required. The flexible sensors can be applied to the skin and can send a variety of data to a smartphone via Bluetooth, including pH, glucose and oxygen levels, and electrical activity in muscles.
The medical utility of wearables becomes clearer with each passing year, but with the cost of living increasing, developing less expensive medical technologies seems wise. This latest technology involves upcycling a largely obsolete technology, compact disks, into something cutting edge, without breaking the bank.
The process involves detaching the metallic layer on a CD from the plastic backing. The researchers achieved this using a chemical process and some sticky tape. “When you pick up your hair on your clothes with sticky tape, that is essentially the same mechanism,” said Ahyeon Koh, a researcher involved in the study. “We loosen the layer of metals from the CD and then pick up that metal layer with tape, so we just peel it off. That thin layer is then processed and flexible.”
The researchers then used a Cricut cutter, a relatively inexpensive consumer machine that is sometimes used by crafters to cut card or paper, to cut the final sensor design from the metallic sheet. Creating the biosensors takes only 20-30 minutes and does not require engineering skills, toxic chemicals, or expensive laboratory equipment. Best of all, each sensor costs about $1.50 to make.
“We used gold CDs, and we want to explore silver-based CDs, which I believe are more common,” said Matthew Brown, another researcher involved in the study. “How can we upcycle those types of CDs with the same kind of process? We also want to look at if we can utilize laser engraving rather than using the fabric-based cutter to improve the upcycling speed even further.”
Study in Nature Communications: Upcycling Compact Discs for Flexible and Stretchable Bioelectronic Applications
