Real-Time Study of Stretching of Molecular Junctions Between Nanoparticles: An Avenue to Build Molecular-Electromechanical Devices

Currently molecular-electronics is mostly conducted on rigid-electrodes which do not conform to the changes in molecular-structure. In this talk, we will demonstrate that nanoscale molecular linkages between gold nanoparticles (GNPs) can function as ‘spring-like' molecular junctions, which under external force exhibit transient and reversible molecular mechanics. Specifically, we will show the mechanism and real-time-dynamics of transient stretching of molecular junctions under controlled centrifugal forces. The device construct presented here is unique since it incorporates (a) interconnected nanoparticles, which act as low-mass mobile nanoelectrodes, which can deform molecules and measure the deformation via change in their electrical properties (electron tunneling) and (b) elastic molecular junctions built by cross-linked polyelectrolyte (poly allyl hydrochloride) rendering the molecular junction with ‘spring-like' ability, where after stretching the molecules apply a restoring force on the nanoparticles to bring them back to their native state. The fundamental insight gained from these molecular electromechanical studies will enable development of next-generation systems such as molecular machines, molecular times and other molecular devices.