Molecule-based microelectromechanical sensors

Abstract

Incorporating functional molecules into sensor devices is an emerging area in molecular electronics that aims at exploiting the sensitivity of different molecules to their environment and turning it into an electrical signal. Among the emergent and integrated sensors, microelectromechanical systems (MEMS) are promising for their extreme sensitivity to mechanical events. However, to bring new functions to these devices, the functionalization of their surface with molecules is required. Herein, we present original electronic devices made of an organic microelectromechanical resonator functionalized with switchable magnetic molecules. The change of their mechanical properties and geometry induced by the switching of their magnetic state at a molecular level alters the device’s dynamical behavior, resulting in a change of the resonance frequency. We demonstrate that these devices can be operated to sense light or thermal excitation. Moreover, thanks to the collective interaction of the switchable molecules, the device behaves as a non-volatile memory. Our results open up broad prospects of new flexible photo- and thermo-active hybrid devices for molecule-based data storage and sensors.

Complete Set of Elastic Moduli of a Spin-Crossover Solid: Spin-State Dependence and Mechanical Actuation

“…[19] Various actuating devices, mainly consisting of bilayer structures where a SCO thin film is coated on a freestanding cantilever, have been then constructed and investigated for their actuating properties in response to the spin-state change of the thin film. [19][20][21][22][23][24][25] Obviously, the actuating performance of these devices, in particular the actuating force and work density, is directly related to the elastic properties (Young's modulus, Poisson's ratio, …) of the SCO material, which need to be accurately characterized.…”

Coupling Mechanical and Electrical Properties in Spin Crossover Polymer Composites

“…has been successfully exploited in the past years to develop mechanical actuators [13,14] integrated into microelectromechanical systems [15][16][17][18] as well as into macroscopic "artificial muscles." [14,19] For these applications, however, the use of electrical stimuli to control (read/write) the spin-state of the system would provide a great advantage due to the easier size reduction and better compatibility with current technology.…”

Sensing of the Molecular Spin in Spin-Crossover Nanoparticles with Micromechanical Resonators

“…Such a device is associated with a low Young's modulus and a high aspect ratio, demonstrating large resonance frequency shifts (sometimes accompanied with hysteresis loops), dominated by the total surface stress, which is consistent with our work. 45 estimated along the cantilever length). Besides, they reported a decrease of approximately spin transition.…”