NASA engineer turned YouTuber Mark Rober has teamed up with scientists from California’s Salk Institute and Brigham Young University to create the smallest ‘Nerf Gun’ models in history, one of which was built from modified strands of DNA.
Rober had previously spent seven years working on NASA’s Curiosity Rover at the agency’s Jet Propulsion Laboratory, before using his engineering talent and penchant for shenanigans to create a viral YouTube channel, which at the time of writing boasts over 25.9 million subscribers.
Seven years ago, Rober went viral after creating the largest Nerf Gun in history. For his most recent video, he took that same concept and sprinted in the opposite direction, by asking scientists to create some of the tiniest Nerf gun models ever.
First up, the YouTuber turned to his alma mater of Brigham Young University, and asked a team of students led by professor Larry L. Howell to design a fully functional miniature Nerf gun that could fit on a human finger.
The tiny scale Rober envisioned for the project meant it would be impossible to design the model using the combination of moving parts and springs that allows an ordinary Nerf Gun to fire its payload of air propelled foam bullets.
Instead, the team opted to design their mini-Nerf out of a single 3D-printed block in order to avoid issues with friction between moving parts. The end result was a fully functional model that could fire a single bullet using a series of inbuilt springs just a couple of centimetres long but still capable of firing a dart a distance of almost three feet.
(The CAD file for the spring-powered Nerf has been made available free online for people with 3D printers.)
Rober then took the design to the University’s micromechanisms lab, where they grew a microscopic functional version from carbon nanotubes 100 times smaller than a regular Nerf pistol. This latest monument to smallness was so tiny it was literally dwarfed by an ant, and could only be fired with the aid of a robotic micromanipulator needle.
The scientists then used the carbon nanotube synthesis tech to grow outlines of Nerf Guns that were 10,000 times smaller than the original, which were a fifth the width of a human hair, and required an electron microscope to view.
For the final step of his quest to make the smallest Nerf Gun, Rober turned to a team of scientists from the Salk Institute led by one assistant professor Pallav Kosuri, and asked them if they could create the outline of one out of nothing more than strands of Deoxyribonucleic acid, or DNA.
DNA is present in the nucleus of most mammalian cells, and serves as an instruction manual for our bodies by telling its constituent parts how they should act to best serve the whole. Most DNA forms a double helix formation when two separate strands featuring billions of complementary chemical bases bind together.
Dr. Kosuri’s lab specialises in manipulating the bases of single strands of DNA known as scaffold strands in a way that forces them to attach to one another and form pre-determined shapes. These strands are locked in place with smaller staple strands, which essentially serve as structural supports to stop the whole assembly unravelling.
Using this technique, Kosuri’s team were able to computer model the outline of a Nerf Gun, and then mixed trillions of the manipulated scaffold DNA strands together with quadrillions of staple strands in a solution where they could naturally combine, and hopefully form the correct shape. After an hour-and-a-half the successfully combined DNA Nerf Guns were separated from the failed strands.
The end result was a drop of water containing 1.2 trillion of the DNA structures, which, when viewed under an atomic force microscope, revealed the outlines of Nerf Guns that were around three million times smaller than the original. According to Rober each of the guns was roughly two-thousandths the width of a human hair, and were made up of just a few thousand atoms.
According to Kosuri, Rober’s Nerf-based shenanegans got his team thinking about similar ways they could manipulate DNA to use as a drug delivery system to treat diseases. “When Mark asked me if we could build a Nerf blaster out of DNA, at first I just thought of it as a fun stunt,” remarked the assistant professor.
“But then I realised that the nano-Nerf idea could actually be a springboard for a useful new technology: if we can create molecular injection devices, then we might one day be able to use these nano-injectors to deliver drugs to cells in a manner that is more effective, precise, and safe than current technologies,” continued Kosuri. “The best inventions are the ones that first make you laugh, and then make you think!"
Check out Mark Rober's YouTube channel for the full video breaking down the scientist's efforts to create the tiniest Nerf models in history.
Image Credit: Mark Rober, Brigham Young University.
Anthony is a freelance contributor covering science and video gaming news for IGN. He has over eight years experience of covering breaking developments in multiple scientific fields and absolutely no time for your shenanigans. Follow him on Twitter @BeardConGamer