A McMaster University scientist has created what’s believed to be the world’s smallest gingerbread house – an intricate structure no bigger than a speck of dust.
Travis Casagrande, a research associate at the Hamilton university, created and assembled the tiny house on the head of an equally teeny snowman using an electron microscope, a device that scientists use to study materials in labs.
The length of the house is 10 micrometres (or 0.01 millimetres), equalling approximately a tenth of the diameter of an average human hair, Mr. Casagrande said.
The project aims to show the marvels of science and inspire youth as much as celebrate the season.
Using the electron microscope that has a focused gallium ion beam, Mr. Casagrande cut the gingerbread house pieces from silicon. He then extracted the pieces by attaching a tiny needle to them. He moved that needle using a microcontroller to pick up the shapes and assemble the house, he said.
The ion beam also etched in details, blasting away materials from the surface. The intricacies of his work include a Canadian flag for a welcome mat, a chimney and defined bricks.
The house, Mr. Casagrande believes, is the smallest of its kind in the world. It’s about half of the size of one made in France last year that was regarded then as the smallest.
His holiday project started when his manager at the Canadian Centre for Electron Microscopy asked him to make a microscopic gingerbread house. Mr. Casagrande suggested taking the idea to another level by constructing the house on top of a snowman.
Mr. Casagrande made his house of silicon while he made the snowman of particles that are used in lithium-ion battery research, including nickel, cobalt and aluminum.
The snowman is much larger than the house. Yet, they both together are barely taller than the diameter of a human hair. “That was to show two scales of operation,” Mr. Casagrande said.
“Travis is a nanometre material surgeon,” said Nabil Bassim, the scientific director at the electron microscopy centre.
“He’s an extremely talented person. … Making that nano-gingerbread house is not a trivial thing to do,” Dr. Bassim added with a laugh.
The goal of the project was to spark a curiosity in science among people and promote science literacy, Mr. Casagrande said. “That’s important for people to make better decisions and for looking at career options."
It also showcases the centre’s tool kit. Researchers from universities, government departments and the private sector can use the centre’s powerful microscopes to look at all kinds of materials, including metals and geological materials, Dr. Bassim said.
The electron microscopes are nano-cutting tools. “We use them, beside making gingerbread houses, to cut very small sections from materials. ... That allows you to look at very specific features,” Dr. Bassim said. “You can see atoms in a crystal stacking up.”
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