Bottom-up assembly of Functionalized Nanohelices: a further step towards flexible devices – NANOHELIFLEX

Gold NPs were synthesized and functionalized with different compositions of insulating ligands and were further grafted on the surface of nanohelices with a covalent bond. The various assemblies obtained are deposited by dielectrophoresis between interdigitated electrodes on a flexible substrate.

The flexibility, sensitivity and stability properties of the sensors are then characterized by electromechanical measurements coupled with scanning electron microscopy observations. Humidity and heat tests have also shown the efficiency of these new sensors.

Confidential

This project has led to the publication of 2 theses and numerous results, some of which are confidential because they are processed in collaboration with an industrial partner.

Low cost strain sensors based on electron tunneling in assemblies of metallic nanoparticles (MNPs) are proposed as a new touch technology for flexible displays, but their sensitivity and stability are still impacted by variations in thickness, morphology and density of NPs films. With an industrial partner NANOMADE Concept, which develops a patented touch technology relying on MNPs-based resistive strain gauges, we propose to develop strain sensors based on the use of nanohelices assemblies coated with conductive nanoparticles interconnected via ligands to be advantageously used to overcome such critical points: the helical morphology exhibits enhanced flexibility that will increase the measurable range of strain; the positioning of metallic NPs with ligands on the nanohelices can be done with a high degree of precision; alignment of highly ordered wires of metallic NPs will be straightforward since they are already positioned on the nanohelices. The aim of this project is to improve the electromechanical properties of strain sensors both in terms of sensitivity as well as reproducibility and stability.