Disposable fabric-based electrochemical sensors fabricated from wax-transfer-printed fluidic cells and stencil-printed electrodes

Abstract

Porous substrates transport fluid via capillary action and can be inexpensive, making them ideal for field-use sensors. Direct wax printing is one of the most commonly used fabrication methods to define fluid paths in standard substrates like cellulose and nitrocellulose. However, direct wax printing is not possible for flexible materials like fabric. In this work, we demonstrate a simple method of creating flexible electrochemical sensors in fabric by (i) wax transfer printing to define the fluidic cell and (ii) stencil-printing to define electrodes. We characterize the wax transfer process in several types of fabric and across two methods of applying heat and pressure to achieve robust fluid boundaries. Finally, we characterize the performance of fabric-based electrochemical sensors created using these methods. The results, in the context of glucose sensing, indicate comparable reproducibility and limit of detection for the fabric-based sensor compared to one implemented in standard cellulose.