Since the dipole-dipole interaction between the induced sample dipole and the image tip dipole varies with ~ 1/z4 dependence where z is the tip-sample spacing, PiFM is expected to provide extreme surface sensitivity. We use PS(polystyrene)-b-PTMSS[poly(4-trimethylsilylstyrene)] block copolymer (BCP) with horizontal lamellae to demonstrate the surface sensitivity. The pitch L0 of the BCP is ~22 […] Read more
The PiFM paper called Photoinduced Force Mapping of Plasmonic Nanostructures from Rice University was featured in an article at phys.org titled “Light provides pull for future nanocatalyst measurement”. The article can be found here.
Our paper titled “Nanoscale chemical imaging by photo-induced force microscopy” is published on the online publication of Science journal, Science Advances, today. The paper introduces infrared PiFM imaging on two block copolymer systems, PS-b-PMMA and PS-b-P2VP. By using infrared wavelengths that correspond to the absorption bands for each of the polymer components, each chemical component […] Read more
Junghoon Jahng et. al. have published a theoretical and experimental analysis of the dominant forces measured in PiFM in a paper titled “Gradient and scattering forces in photoinduced force microscopy.” They conclude that both optically induced dipole-dipole gradient force (Fg) and scattering force (Fs) are present in a typical PiFM setup. Whereas Fs is insensitive to […] Read more