Above: Two microstructures made with the new material, containing the highest concentration of RDGE. Left: Pre-charring. These pyramid and bunny models did not respond to the preferred method of 3-D shaping, so they were created using an alternative process. Right: Post-charring. Notice that the pyramid and bunny shrink significantly less than those made from the material with a lower concentration of RDGE.
The team of scientists use a new material that can be molded into complex, highly conductive 3D shaping structures just a few micrometers across.
According to The Optical Society: The researchers also tested their new resin's ability to be manipulated using techniques specifically suited for 3-D shaping. In one technique, called microtransfer molding, the light-sensitive liquid was molded into a desired shape and then hardened by exposure to ultraviolet (UV) light. The other technique, preferred because of its versatility, made use of the liquid resin's property of solidifying when exposed to a laser beam. In this process, called two-photon polymerization, researchers used the laser to “draw” a shape onto the liquid resin and build it up layer by layer. Once the objects were shaped, they were carbonized and viewed with a scanning electron microscope (SEM).
In addition to crafting pyramids and discs, the researchers reproduced the well-known “Stanford bunny,” a shape commonly used in 3-D modeling and computer graphics. Maruo says that when he first saw a picture of the rabbit structure taken with the SEM, he was delighted at how well it had held up during the charring process.
“When we got the carbon bunny structure, we were very surprised. Even with a very simple experimental structure, we could get this complicated 3-D carbon microstructure. The rabbit's shape would be much more difficult, expensive, and time-consuming to create using any of the existing processes compatible with carbonization.”