World’s Smallest Nerf Gun Shoots an Ant

The script introduces a project to create the world's smallest Nerf gun, a significant engineering challenge. The narrator has spent a year developing this minuscule toy, which can still cock and fire a dart. The goal is to shrink the size of the Nerf gun by a factor of ten at each stage, aiming to eventually fit five of them across the width of a single human hair. The first issue addressed is the complexity of the Nerf gun's mechanism, which consists of 87 parts, 13 springs, and six hinges. The challenge is to create a functional Nerf gun using a single part without springs. The narrator visits his alma mater, BYU, to collaborate with students and experts in the field of mechanical engineering, particularly focusing on 'compliant mechanisms' that can replace springs with flexible parts made from a single piece.

The narrator discusses the concept of compliant mechanisms, which are flexible single-piece structures that can replace traditional mechanical springs and hinges. The benefits of such mechanisms include fewer parts, lower cost, precision, lower weight, reduced friction, and built-in springiness. The script details the process of designing a full-size template and then scaling it down, with the aim of creating a Nerf gun that can store energy without mechanical springs. After numerous prototypes, three designs are considered: a zigzag, a fishbone, and a final design with longer ribs for more power. The final design is made from a metallic alloy, which can store more energy and fire a dart more powerfully than a regular Nerf gun. The project then successfully sets a world record for the smallest Nerf gun, which can fire a dart a scaled-down distance, and the CAD files are made available for others to replicate the project.

The script continues with the ambitious task of further miniaturizing the Nerf gun, this time to a size 100 times smaller than a normal Nerf gun, using a process known as 3D micro printing. The narrator returns to BYU to work with a team in the Micro Mechanisms lab and uses a microscope to manipulate the minuscule Nerf gun. The gun is made from carbon nanotubes, a material chosen for its precision and small scale. The team successfully fires the tiny Nerf gun, marking another world record. They also discuss the possibility of creating an even smaller version, 1000 times smaller than a normal Nerf gun, and the script ends with a playful interaction with an ant, hinting at the scale of the project.

The script describes the use of DNA origami to create the smallest Nerf guns yet, this time at a scale of 10,000 times smaller than a normal Nerf gun and even further down to 3 million times smaller. The process involves using DNA as a building material, designing the shape on a computer, and then using staple strands of DNA to lock the scaffold strand into the desired shape. The DNA self-assembles into the shape of a Nerf gun at a temperature-controlled environment. The final product is so small that it requires an atomic force microscope to be visualized. The script also hints at the potential medical applications of this technology, suggesting that it could be used for targeted treatments for diseases by delivering specific DNA to cells.

The script concludes with a reflection on the significance of the Nerf gun project as a symbol of the innovative and creative work being done by engineers and scientists worldwide. It emphasizes the importance of dreaming up big ideas and the courage to turn those dreams into reality, as exemplified by Jonas Salk and others. The narrator promotes the CrunchLabs build box, a subscription service that encourages creative thinking and learning through the assembly of toys, with the added incentive of a platinum ticket for a chance to visit the lab. The script ends on a hopeful note, celebrating the potential of scientific research to improve future generations' lives.