ORNL researchers developed an innovative imaging method that possesses the imaging capability of scanning near-field ultrasound holography and the chemical specificity of reverse photoacoustic spectroscopy. This imaging method can achieve chemical differentiation with nanometer resolution. Atomic force microscopy is a well established technique for imaging surface features of a nanometer or less. In conventional methods, a cantilever has a tip capable of making a nanometer sized contact. However, any small variation in distance between the probe and the sample surface can result in a large change in the contact force between the probe’s tip and the sample. To address this challenge, the invention includes two independent oscillators and is able to distinguish the frequencies of the two acoustic waves applied to the probe. In addition, electromagnetic energy is applied to the sample, causing a change in phase of the second acoustic wave. The device can also be used for determining chemical characteristics of a sample by applying different acoustic waves.
ID: ID 2174License Status
ID 2174: Scanning Probe Microscopy with Spectroscopic Molecular Recognition