Construction of a twin-pier platform for biological sensing

This paper describes the successful construction of a twin-pier platform for use in biological sensing applications. The two piers are inline and have a tunable gap between them, with gap distance varying between 60-200 nm. The proximal ends of the piers are contiguous with a Co-Planar Waveguide structure that allows for testing. The basic pier structure was created by ablation of a customized MMA/PMMA stack using a JEOL laser system. A layer of Ti-Au was then deposited on silicon using standard electron beam deposition techniques. Electromagnetic testing of the structures was correlated with SEM imagery for characterization of electrical properties and gap integrity. The overall design is to create a biological sensing bridge by tethering molecules across the distal ends of the piers thereby completing the circuit. The type and composition of biological bridge provides sensor selectivity and sensitivity.