Dynamics of interacting graphene membranes

Micro and nanomechanical sensors are indispensable in modern consumer electronics, automotive and medical industries. Gas pressure sensors are currently the most widespread membrane-based micromechanical sensors. By reducing their size, their unit costs and energy consumption drops, making them more attractive for integration in new applications...

Fiber-optic Fabry-Pérot interferometers for axial force sensing on the tip of a needle

A range of complex percutaneous procedures, such as biopsy or regional anesthesia, rely heavily on accurate needle insertion. Small variations in the mechanical properties of the pierced tissue can however cause deviations from the projected needle path and can thus result in inaccurate placement of the needle. Navigation of a rigid needle...

Comb mode filtering silver mirror cavity for spectroscopic distance measurement

In this work we present a design of an external optical cavity based on Fabry-Perot etalons applied to a 100 MHz Er-doped fiber optical frequency comb working at 1560 nm to increase its repetition frequency. A Fabry-Perot cavity is constructed based on a transportable cage system with two silver mirrors in plano-concave geometry including the...

Fiber-optic Fabry-Pérot interferometers for force sensing on the tip of a needle

Physicians use small variations in the needle insertion force to identify tissue properties and detect membrane punctures during needle insertion. Navigation of a needle towards the target tissue, for example to take a biopsy, is often based on detecting these variations in force. Literature shows that presenting physicians force feedback based...

Design of a folded, multi-pass Fabry–Perot cavity for displacement metrology

We present a folded, multi-pass cavity design for displacement measuring Fabry–Perot interferometry. The cavity length is designed to be one-quarter of the physical length needed for a typical Fabry–Perot interferometer by using a quarter-wave plate and a retroreflector. This enhances the displacement sensitivity by a factor of four, allowing...

Simple optical characterisation for biomimetic micromachined silicon strain-sensing structure

This paper presents an on-going work to develop micromachined silicon-based strain sensor inspired from the campaniform sensillum of insects. We present simple optical setup for the characterisation of a membrane-in-recess structure as an early stage in mimicking the natural sensor. The microstructure is a 500 nm-thick SiO2/SiN circular membrane...