NanoSim

See the nanoscale.
Then reach in.

NanoSim is a free science lab for things too small to see. Grow gold nanoparticles, melt an ice crystal molecule by molecule, and watch a living cell swallow a particle you designed.

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Move your cursor through the particles. You are the microscope tip.

Three labs, one question each

The Nanoparticles lab: gold particles in a chamber of water, some clumped together, with a purple beaker and Pip's mission card.
Nanoparticles lab

Why is nano-gold red?

Nanoparticles

Grow gold, silver, quantum dots, magnetite or silica in a 2 µm chamber of water. Add salt and watch them clump. The beaker shows the colour you would really see.

  • Zoom from a human hair down to single atoms
  • Push particles around with an AFM tip
  • Measure atom counts, surface share and melting point
The Water molecules lab: a hexagonal ice crystal melting at its edges, with hydrogen bonds drawn as dashed lines.
Water molecules lab

Why does ice float?

Water molecules

Build a 3 nm ice crystal and heat it. The edge melts first, because molecules on the surface have fewer neighbours holding on to them.

  • See every hydrogen bond form and break
  • Cool liquid water slowly into hexagons
  • Hear the crystal freeze and melt
The Cell membrane lab: a gold nanoparticle being wrapped by a cell membrane, with a chart of entry time against particle size.
Cell membrane lab

How does medicine get into a cell?

Cell membrane

Design a nanoparticle and release it at a cell. Too small and it bounces off. Too oily and it gets stuck. Just right, and the cell wraps it up and pulls it inside.

  • Choose size, shape, charge and coating
  • Find the size that enters fastest
  • Built on published membrane models

Real physics behind every pixel

The cartoons are optional. The numbers are not. Each lab runs on a model from the scientific literature, and the app tells students where the model stops being right.

What you seeWhat decides itSource
Particles wander and never sinkBrownian motion, Stokes–Einstein diffusionEinstein, 1905
Gold is red, then blue when clumpedPlasmon absorption and the eye's colour responseHaiss et al., 2007; CIE, 1931
Quantum dots glow by sizeMeasured sizing curve, compared with the Brus modelYu et al., 2003; Brus, 1984
Small gold melts earlySurface atoms are loosely heldBuffat & Borel, 1976
Ice forms hexagons and floatsDirectional hydrogen bonds, Monte CarloSilverstein, Haymet & Dill, 1998
A cell wraps the right-sized particleMembrane bending versus adhesion energyGao, Shi & Freund, 2005; Zhang, Ma & Wei, 2021

Made for classrooms

A guide for younger learners
Pip, a cartoon gold nanoparticle, leads kids through 8 missions with badges. Restart the tutorial any time to practise again.
A plain lab for older students
Switch the cartoons off and every panel shows the measurements, equations and sources.
Private by design
No email, no real name, no ads and no tracking. A nickname and a password are all it keeps.
Light on school Wi-Fi
No outside scripts, fonts or trackers to load. Runs in any modern browser, on laptops and phones.
Pip, the NanoSim mascot, waving.

Ready to shrink down?

Line up 4,000 gold nanoparticles and they would span one human hair. Come and meet them.

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