Highest Resolution in Microscopy
The highest resolution in microscopy is currently achieved by techniques in electron microscopy, particularly through the method known as High-Resolution Transmission Electron Microscopy (HRTEM). This technique allows for the visualization of the atomic structure of materials, reaching resolutions down to less than 0.1 nanometers (nm).
HRTEM operates by transmitting a high-energy electron beam through a very thin specimen. The electrons interact with the specimen's atoms, producing an image that can reveal the arrangement of atoms within the material. The resolution limit of HRTEM is primarily determined by the wavelength of the electrons, which is much shorter than that of visible light, allowing for much higher resolution.
Another advanced technique contributing to high-resolution microscopy is Scanning Transmission Electron Microscopy (STEM), combined with aberration correctors. These correctors compensate for lens imperfections, pushing the resolution limit even further, to the order of 50 picometers (pm).
Moreover, the development of cryo-electron microscopy (cryo-EM) has been revolutionary, especially in the field of biological microscopy. Cryo-EM allows for the observation of biological specimens in their native hydrated state at near-atomic resolutions. In 2017, the Nobel Prize in Chemistry was awarded for the development of cryo-EM, which can achieve resolutions of around 1.2 to 3.5 angstroms (Å) in practical applications, allowing scientists to visualize proteins and biomolecules at unprecedented detail.
It's important to note that the highest achievable resolution in microscopy is constantly evolving with technological advancements and the development of new techniques.