Stamp transfer electrodes for electrochemical sensing on non-planar and oversized surfaces

This article describes a new alternative approach to the fabrication of printed electrochemical sensors and biosensors based on the transfer of electrode patterns comprising common conductive and insulating inks from elastomeric stamps to a wide variety of rigid and flexible substrates. This simple, low cost, yet robust methodology is demonstrated to be well-suited for the formation of electrochemical sensors on non-planar substrates and large objects/structures, which have traditionally been off-limits to conventional screen printing techniques. Furthermore, the stamped electrode devices are shown to exhibit electrochemical performance that rivals that of their screen printed counterparts and display resilience against severe mechanical deformation. The stamp transfer approach is further extended to the demonstration of epidermal electrochemical sensors through the transfer of the electrode patterns directly onto the skin. The resulting sensors demonstrate a wide range of usability, from the detection of various physiological analytes, including uric acid on the skin, to the identification of residues originating from the handling of munitions and explosives. The migration of printable electrochemical sensors to non-conventional (non-planar and/or oversized) surfaces provides new opportunities within the personal healthcare, fitness, forensics, homeland security, and environmental monitoring domains.