Low Temperature Packaging for Ion-Sensitive Organic Field Effect Transistor

Low temperature packaging between flexible organic field-effect transistor (OFET) and sensing elements is a great hurdle to ion-sensitive organic field-effect transistor (ISOFET) for practical applications. Here, a low temperature (<80 ° C) packaging method for ISOFET was proposed by flip-chip bonding OFET and working/reference electrodes on plastic carrier using silver paste as the conductive adhesive. A hollow structure was adopted to prevent OFET from damaging by solvents in the adhesive. A flexible ion-sensing tag consisting of 3-channel ISOFETs was demonstrated to properly detect Na+, K+, and H+ions.