Interfacing electrochemical sensors in lab-on-a-disc (LoD) system with a potentiostat is often tedious and challenging. We here present the first multichannel, modular, lightweight and wirelessly powered, custom-built potentiostat-on-a-disc (PoD) for centrifugal microfluidic applications. The developed potentiostat is in the form factor of a typical DVD and weighs only 127 g. The design of the potentiostat facilitates easy and robust interfacing with the electrodes in the LoD system, while enabling real-time electrochemical detection during rotation. The device can perform different electroanalytical techniques such as cyclic voltammetry, square wave voltammetry, amperometry while being controlled by custom-made software. Measurements were conducted with and without rotation using both inhouse fabricated and commercial electrodes. The performance of the PoD was in good agreement with the results obtained using a commercial potentiostat with a measured current resolution of 200 pA. As a proof-of-concept, we performed a real-time release study of an electrochemically active compound from microdevices used for drug delivery.

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We use the principles of cavity opto-mechanics to design a resonant mechanical force sensor for atomic force microscopy. The sensor is based on a new type of electro-mechanical coupling, dual to traditional capacitive coupling, whereby the motion of a cantilever induces surface strain that causes a change in the kinetic inductance of a superconducting nanowire. The cavity is realized by a compact microwave plasma mode with an equivalent LC circuit involving the nanowire's kinetic inductance. The device is fully co-planar and we show how to transform the cavity impedance for optimal coupling to the transmission line and readout circuit. For the device presented here, we estimate the bare Kinetic Inductive Mechano-Electric Coupling (KIMEC) rate g0/2π ∼ 3-10 Hz. We demonstrate phase-sensitive detection of cantilever motion using a multifrequency pumping and measurement scheme.