The work presented details the manufacturing of a low-cost hybrid inkjet-printed paper-based potentiostat, with the aim of creating a low-cost sensing system for rapid water quality monitoring. Potentiostats exhibit high sensitivities and can be used for a variety of applications. The results highlight the functionality of a paper-based potentiostat compared to a potentiostat manufactured on a printed circuit board (PCB), an LMP91000EVM development board and a laboratory-based Metrohm Autolab potentiostat. Cyclic voltammetry was performed using an 80 µL sample of 5 mM ferri-ferrocyanide dropped onto a commercial screen-printed electrode from DropSens. The miniaturized paper-based potentiostat is small enough to be stored in a wallet and therefore easy to transport. Furthermore, a cost analysis shows that the potentiostat is 10 times lower in cost than the commercially available handheld potentiostat, taking the costs of man hours into account. This technology enables electrochemistry experiments to be performed on-site using the portable, disposable and low-cost solution and can be applied to a variety of fields including healthcare, wearables and environmental monitoring.
This work details manufacturing processes developed to integrate an unpackaged silicon die onto a paper substrate, as part of constructing a hybrid inkjet‐printed paper‐based circuit. This integration between rigid components and flexible substrates is beneficial in low‐cost applications and capitalises on the advantages of both the well‐established integrated circuit technology and the emerging paper‐based electronics platforms. A superglue incline at the chip edge formed a ramp for printing the silver interconnects between the paper‐based circuit and the chip pads. Two printing protocols are compared, the first a single layer using 5 μm drop spacing, and the second using a 35 μm drop spacing for three layers. An unpackaged RFID tag die is successfully integrated and is presented as proof of concept.