Inkjet printing of flexible interdigitated electrodes using an office inkjet printer for chemi-resistive glucose sensing*

A comb-like structure called an interdigitated electrode is the basic building block of a chemi-resistive sensor. The response of the sensor to a chemical is characterized by the electrical resistance measured between the electrodes. Ink-jet printing has been developed as an attractive rapid fabrication technique of interdigitated electrodes. However, such advanced inkjet printers are not readily available for researchers to develop sensing platforms for rapid prototyping. Moreover, the steep learning cycle of such dedicated printers limits the user group. In this regard, the use of an office desktop inkjet printer for fabricating interdigitated electrodes was considered. The interdigitated electrodes were printed on Polyethylene terephthalate (Novele IJ-220 - PET) substrate using EPSON L130 desktop piezoelectric ink tank printer with commercial silver conductive ink (Metalon JS-B25P). A thin film of cuprous oxide nanoparticles was drop-casted onto the electrode and tested for glucose sensing. The evaluation of the performance of the sensor suggested that the technique is an economically viable alternative to the use of high-end dedicated inkjet printers to fabricate sensors for applications including detecting medical parameters and food spoiling.