Graphene-based inkjet printing of flexible bioelectronic circuits and sensors

Abstract

Bioelectronics involves interfacing functional biomolecules or living cells with electronic circuitry. Recent advances in electrically conductive inks and inkjet printing technologies have enabled bioelectronic devices to be fabricated on mechanically flexible polymers, paper and silk. In this research, non-conductive graphene-oxide (GO) inks are synthesized from inexpensive graphite powders. Once printed on the flexible substrate the electrical conductivity of the micro-circuitry can be restored through thermal reduction. Laser irradiation is one method being investigated for transforming the high resistance printed GO film into conductive oxygen reduced graphene-oxide (rGO). Direct laser writing is a precision fabrication process that enables the imprinting of conductive and resistive micro-features on the GO film. The mechanically flexible rGO microcircuits can be further biofunctionalized using molecular self-assembly techniques. Opportunities and challenges in exploiting these emerging technologies for developing biosensors and bioelectronic cicruits are briefly discussed.