Adaptive Fibre Organic Electrochemical Transistor for Volumetric Embedded Sensing in Organ-on-a-Chip

Three-dimensional (3D) organ-on-a-chip models, which aim to recreate key in vivo, physio-pathological behaviours of organs on microfluidics, have become an important platform for fundamental research and for pharmaceutical testing. As these in vitro models increase in size and complexity, it is paramount to find means of monitoring the dynamics of tissue states in thick sections. Although various transistors and sensors have been developed to integrate with 3D cell cultures, their pre-set formats limit their adaptation and utilisation in a wide range of organ-on-a-chip contexts. Here, an ultra-flexible fibre organic electrochemical transistor (ufOECT) is fabricated to perform volumetric sensing in diverse formats of 3D cultures and organ-on-a-chips. With a diameter of ~30um, and a length adjustable between millimetres to centimetres, the ufOECT can be twisted, curved, or straightened for embedding into a cell culture device for in situ monitoring of effective tissue matrix impedance. It is envisaged that ufOECT could be developed into a powerful tool for low-cost, scalable, label-free and sustainable monitoring organ-on-a-chip devices.