Design and fabrication of a multiple-thickness electrochemical cantilever sensor
Résumé
In the last decades, the ability of cantilever sensors to detect a wide range of molecular interactions has been demonstrated. Recently, various groups have focused on improving the performance of cantilever-based sensing by introducing an electrochemical actuation. The cantilever deformation is usually interpreted through Stoney's equation, which is however questionable when dealing with chemically- induced effects. To address this issue, alternative mechanical frameworks have been proposed, featuring different relationships between the cantilever's thickness and the shape of the displacement field. Experiments probing the role of the cantilever's thickness are thus required. However, it is extremely challenging to achieve micro-fabrication of multiple-thickness cantilever beams on a single chip and simultaneously ensuring its combined electrochemical and mechanical capabilities as well as the necessary accessibility for optical readout, electrical connection, and fluid access in real-time deflection measurements. Here, we describe the design and fabrication of a multiple-thickness cantilever sensor platform, in order to verify the role of the cantilever's thickness on the chemically-induced mechanical effects.