mecwins. Innovation in nanomechanics for biotechbology

The technology, which combines very short response times with very small sample consumption, uses thebimetallic effect to detect thermal transitions. Specifically, abrupt variations in the Young’s modulusand the thermal expansion coefficient produced by temperature changes have been employed todetect thermodynamic transitions. The technology has been used to determine the glass transitionof poly(3-thiophene methyl acetate), a soluble semiconducting polymer with different nanotechnological applications. The glass transition temperature determined using microcantilevers coated withultra-thin films of mass = 10−13 g is 5.2◦C higher than that obtained using a conventional differential scanning calorimeter for bulk powder samples of mass = 5 × 10−3 g. Atomistic molecular dynamics simulations on models that represent the bulk powder and the ultra-thin films have been carried out to provide understanding and rationalization of this feature. Simulations indicate that the film-air interface plays a crucial role in films with very small thickness, affecting both the organization of the molecular chains and the response of the molecules against the temperature. © 2013 AIP Publishing