A group of scientists from Leiden University in the Netherlands recently made a miracle: They have built the world’s smallest boat with a size of only 30 micrometres. So you can imagine how small the boat is, the diameter of a human hair is about 180 micrometres.
Basically, this boat can float on the surface of a single strand of hair.
The micro boat was built for a study called “3D printed colloidal micro-sized swimming objects use catalytic propulsion“published in the Soft Matter magazine.
This study aims to demonstrate a new 3D printing technology can help humans build microscopic objects, mimicking objects swimming in nature also microscopic size such as bacteria or sperm. .
When 2 particles of light meet in a transparent mass
To be able to build a boat the size of micormet, scientists have to use a special 3D printing technology called “two-photon polymerization -2PP “ (polymerization by two photons).
This is an extremely advanced and artistic material sculpting technology that takes advantage of the photocatalytic reactions of polymeric photosensitive materials.
First, scientists will choose a transparent photosensitive object that can pass light into it. They then shone the first light inside the material, halfway through the process of turning the material into a polymer.
For the other half of the polymerization to take place, a second light is directed into the material’s lumen. At the intersection of the two rays, the polymerization reaction takes place completely, turning the photosensitive material into a polymer. This entire process creates a plastic-like deposition point that is emitted from the needle tip of a 3D printer.
In other words, 2PP uses the very ends of the light beam to replace the needle tip of the 3D printer. It is therefore possible to print extremely small objects, down to the micrometer size, with the resolution of each deposition point reaching 100 nm.
Supporting this process are extremely powerful emitting photon beams. The scientists used lasers that can emit pulses in extremely short times, about femtosecond size (10-15 seconds) with maximum capacity up to 200 GW. For comparison, the total installed power source capacity of the entire power system of Vietnam by the end of 2019 will reach nearly 55 GW.
Model of Tokyo Sky Tree Tower
The 2PP technology has previously been used by scientists to create microscopic objects, like a model of the Tokyo Sky Tree, a Tower Bridge of London or a castle on a pencil as you saw above.
But a team of scientists at Leiden University think they can even use it to build animal objects that could be micrometre sized that mimic the way bacteria or sperm move. .
“By controlling and controlling the laser transmittance inside the transparent material, we can print out whatever shape of the swimmer we want.“, Said Daniela Kraft, a member of the research team
Benchy boat can swim on a single hair
In order to realize their ideas, Kraft and colleagues used 2PP technique to create a Benchy boat. Explaining why he chose this boat model, Kraft said Benchy is a boat that anyone who owns a 3D printer must have.
It is a standard model, containing many difficult constructions with 3D printed needles such as arcs, open chambers and windows. With the successful printing of a Benchy boat model, you can be sure that your 3D printer is working properly.
“That’s a natural thing for a micro-3D printer like ours “, Fraft said. “In addition, it is also very interesting to build a boat of micrometer size that can swim.
That’s right, not only at printing a motionless object, Kraft’s team also aims to equip them with propulsion.
After the swimming objects were successfully fabricated, they coated their surface with a super thin layer of platinum (Pt). And because platinum can catalyze hydrogen peroxide (H2O2) decomposes into water and O2When the object is released into water with 10% hydrogen peroxide phase, it will be able to move by the jet of the generated O2.
Although this engine is not yet “installation” On the Benchy, but theoretically, Kraft was able to prove that it would help his boat swim. The team fabricated spherical and spiral objects, coated them with platinum and dropped them in water with 10% hydrogen peroxide, resulting in very special paths:
Scientists hope that the motion patterns of these micro objects will help us better understand the complex movements of bacteria or sperm in the human body. Recently, for example, a team of scientists discovered a very strange pattern of sperm motions, believed to have been demolish the theory that existed for 300 years about their swimming style.
Back to the Benchy boat that Kraft’s team built. Despite not being equipped with a propulsion, but with a size of only 30 micrometres, it now officially sets a record – becoming the smallest boat in the world ever built.