Showing Spotlights 1 - 8 of 107 in category All (newest first):
Scanning probe lithography techniques rely on the use of cantilevers to pattern sub-100 nm structures generated by the mechanical contact between a cantilever tip and a surface. SPL, with its high resolution, is a popular method for prototyping nanoscale structures. Overcoming the current limitations of SPL - the lack of high-resolution, high-speed throughput at low cost - researchers developed a new technique they termed nanocalligraphy scanning probe lithography.
Oct 28th, 2021
Relying on the quantum confinement effect, the strong light-matter interaction in low-dimensional materials enables them to exhibit excellent photodetection. The unique out-of-plane van der Waals force in low-dimensional layered materials makes them free from the surface dangling bonds compared to traditional bulk materials, which reduces the dark current of the devices by eliminating surface recombination. These unique advantages make low-dimensional materials have the potential to achieve breakthroughs in the field of low-cost high-performance room-temperature infrared detection.
Jun 7th, 2021
Taking advantage of its piconewton force and sub-nanometer displacement resolution, atomic force microscopy (AFM) is uniquely suited to measure nanoscale mechanical properties, especially when it comes to soft materials. Force spectroscopy is a useful nanomechanical technique to obtain both single point measurements and maps of important mechanical properties such as stiffness and adhesion. Cantilever and tip calibrations coupled with contact mechanics models enable the full analysis and interpretation of individual force curves.
Oct 30th, 2020
High-entropy alloys (HEAs), which are formed by combining nearly equal parts of several primary metals, are an emerging class of advanced materials that hold great potential for creating materials with superior mechanical, thermal, and catalytic properties. New research offers key insights into how HEA nanoparticles behave under high-temperature oxidizing environment and sheds light on future design options of highly stable alloys under complex service conditions.
Oct 29th, 2020
Atomic force microscopy (AFM) is one of the newer techniques available for virus research. AFM is a cantilever-based technique that utilizes a sharp tip to interrogate surfaces at resolutions well below the optical diffraction limit. Beyond imaging, AFM is also a powerful tool for nano-mechanical probing and nano-manipulation. One of the primary advantages of AFM is that it can operate on samples immersed in liquid. This empowers experiments on living cells at physiologically relevant conditions.
Oct 23rd, 2020
Kelvin probe force microscopy (KPFM), also known as surface potential microscopy, is one member of a suite of electrical characterization methods available in atomic force microscopes. It maps the contact potential difference between a surface and the cantilever, containing information about the surface potential and work function. KPFM is a surface-sensitive method that probes at and near the surface only. It is often used as a qualitative technique to obtain contrast based on the surface potential.
Oct 21st, 2020
The foremost atom of the tip in a scanning probe microscope is critically important for precise imaging results. In atomic force microscopy, the front atom significantly affects atomic-scale contrast and atom manipulation. The chemical species is a dominant factor in determining the tip state, and in situ chemical identification of a tip apex remains a challenging task. Researchers found that Pauling's equation is applicable to the analysis of tip apex atoms. The team also demonstrated a way to determine electronegativity of surface atoms solely by experiments.
Feb 21st, 2020
Two-dimensional (2D) materials could offer new building blocks for future technologies, but this requires approaches to control the carrier type in 2D semiconductors. A number of pioneering works have demonstrated different methods to program the carrier type in 2D materials, such as electrostatic doping, chemical doping, ion implantation, charge transfer, and annealing control. Recently, a team of researchers have developed a technique to dope 2D materials for redefinable nanoelectronics using nonvolatile ferroelectric domains.
Feb 20th, 2020