The challenge
Today's microscopes use in-built magnification scales for routine calibration. However, recent advancement in high-resolution technologies is challenging the accuracy of such scales for quantitative measurements.
The challenge is to find standard specimens or materials that can precisely assess imaging and instrument performance, from the scale of optical and super-resolution imaging to high-resolution and cryo-electron microscopes. In particular, there is a specific need to identify a material with nanoscale features repeated over microscopic length scales.
The solution
A team at NPL designed and developed a series of near-crystalline protein nanostructures assembled from geometrically consistent building blocks to meet this need.
We engineered a microscopic specimen exhibiting single-nanometre spacings with fixed structure. These properties make the material an ideal candidate for a calibration standard that can be used to measure materials on a very small scale.
The impact
These rulers are proteins whose width and pitch are defined at the nanoscale, and are universal for all of this type of protein regardless of origin and function, which ensures reproducibility.
The technology is being assessed by industry to address market needs for calibration standards. The market is currently dominated by inorganic, hard materials, while the demand for soft matter applications and products is steadily increasing.