Ab-initio and Multiscale Study of Surface Stresses from Alkanethiolate Self-Assembled Monolayers on Gold

The self-assembled monolayers (SAMs) absorbed on surface attract much attention due to their diverse applications for biosensing, biorecognition and molecular electronics. In this work, we study absorption-induced surface stresses and microcantilever motion in Alkanethiolate SAMs on Au surface. A multiscale method is developed to link atomistic information with continuum description. The adsorption mechanisms of bio-molecules for SAMs adsorbed on Au are studied through ab-initio simulation. Adsorption-induced stresses for different SAMs are calculated by the multiscale method developed herein. Calculated deflection based on the adsorption-induced stress agrees with experimental measurements. The results give insight into the atomic forces and positions that play a key role in producing adsorption-induced surface stresses and resultant mechanical bending of microcantilevers.