Fraunhofer FEP, ISIT Develop Metal-coated Polymer Film for Affordable Biosensors

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP and the Fraunhofer Institute for Silicon Technology ISIT have successfully developed and tested flexible electrochemical biosensors on metallized film substrates.
 
Fraunhofer FEP has the technology to provide polymer films with a thin metal layer, which is based on a roll-to-roll process. A high degree of uniformity of the layer‘s thickness and a lack of defects represent particular technological challenges in this manufacturing process.
 
The growing market for wearable devices requires a high number of small, lightweight and high capacity sensors for different applications in sport, medicine or at work. Especially useful are so-called “wearables” such as functional wristbands, which provide practical assistance while barely being felt. These devices can monitor body function and provide valuable information. In addition, the electronics should adhere flexibly to the arm.
 
Within Fraunhofer ISIT, the business fields Medical Sensor Systems and Wearables and Printed Electronics cooperate in investigating how silicon-based sensor technologies can transfer to flexible modules and integrate into body-shape sensor systems. Fraunhofer FEP has considerably advanced this development by providing metallized film substrates, with Fraunhofer ISIT developing a flexible electrochemical sensor with which good results could be attained.
 
The sensor measures 8 x 10 mm² and contains an array of electrodes for biological immunological tests. The special feature: the sensor’s thickness is only approximately one tenth of a millimeter as it was produced entirely on a polymer film, which had previously been coated at Fraunhofer FEP. The researchers at Fraunhofer FEP have a lot of experience in coating polymer filmss without defects and with a high degree of uniformity in highly productive roll-to-roll processes.
 
“Polymer films are especially well suited for such applications as they are light weight, flexible and biocompatible,” said Dr. Matthias Fahland. “The results are encouraging even if some hurdles must be overcome still in order for such biosensors to be produced affordably in roll-to-roll processes. We at the Fraunhofer FEP with our processes and facilities are ideally positioned for further research in this promising field. ”
 
Both institutes will work together more closely in the future in order to develop tailor-made flexible electronics for the products of the future together with customers from industry. There are, for example, developments to integrate polymer films-based lactate sensors in wristbands. Thus it would be possible to monitor the wearer’s fatigue during exercise through correlated lactate concentration in sweat.