Cantilever-based sensing: the origin of surface stress and optimization strategies

Abstract

Many interactions drive the adsorption of molecules on surfaces, all of which can result in a measurable change in surface stress. This article compares the contributions of various possible interactions to the overall induced surface stress for cantilever-based sensing applications. The surface stress resulting from adsorption-induced changes in the electronic density of the underlying surface is up to 2-4 orders of magnitude larger than that resulting from intermolecular electrostatic or Lennard-Jones interactions. We reveal that the surface stress associated with the formation of high quality alkanethiol self-assembled monolayers on gold surfaces is independent of the molecular chain length, supporting our theoretical findings. This provides a foundation for the development of new strategies for increasing the sensitivity of cantilever-based sensors for various applications.

Structural changes during the overoxidation of electrochemically deposited poly(3,4-ethylenedioxythiophene) films

“…The "bending beam" method [39][40][41][42][43][44][45][46][47][48][49][50][51] can be effectively used in electrochemical experiments, since the changes of the stress (g f ) in a thin film or other conducting layer on one side of an insulator (e.g. glass) strip in contact with an electrolyte solution can be estimated from the changes of the radius of curvature of the strip.…”

Nanoparticle Structure by Coherent X-ray Diffraction

“…52,53) In experiments on 200-nm-sized-grained films it was also found that the stress takes several hours to build. 54,55) Such cantilevers have important medical applications as sensors. 56) The fact that such large stress differences were detected in the CXD experiment indicates that the structure of the SAM must be very different between the flat and the curved surface regions of the nanocrystal.…”

Detection of viruses using piezoelectric cantilevers

“…Известно, что взаимодействие меж ду виру-сом и рецепторным слоем на поверхности дат-чика обуславливает дополнительные напряже-ния в пленке [14] или повышение эффективной жесткости системы в целом [13]. Это как раз и приводит к увеличению резонансной частоты.…”

“…It is known that the interaction between the virus and the receptor layer on the sensor surface causes additional strain in the film [14] or an increased effective stiffness of the whole system [13]. This results in an increased resonance frequency.…”