Research illustrates that a marginal layer of polyvinyl alcohol can assist in fine-tuning the microstructure of parts for two-photon polymerization lithography.
With the evolution of 3D printing technology, fascinating advancements are being witnessed at incredibly minuscule scales. This brings into discussion the procedure known as two-photon polymerization lithography (TPL), which bears similarities to the photolithographic process practiced in integrated circuit manufacturing.
Seeing that TPL has the potential to create intricate items on the micro and nano scale, it has been employed to create new optical materials, such as photonic crystals.
The shrinkage issue is a significant challenge for TPL, especially when it comes to ensuring uniform shrinkage for features smaller than the wavelength of visible light. An engineering team from Singapore University of Technology and Design (SUTD) and the Industrial Technology Center of Wakayama Prefecture in Japan has proposed a novel method to guarantee uniform shrinkage in 3D-printed structures during heat treatment.
The solution is rather straightforward: applying a layer of polyvinyl alcohol (PVA) to the primary printing substrate. This modification made it easier for them to rinse off 3D-printed components and relocate them onto a different substrate. The team discovered that looser attachment facilitated by the PVA layer resulted in more uniform shrinkage. This also indicated the potential of transferring microscopic 3D-printed parts for integration with other devices, or onto substrates unfit for TPL.
“We reasoned that we could facilitate our 3D structures to ‘glide’ to a smaller size without distortion, similar to the way earthworms stretch and contract to move across surfaces,” Joel Yang, a professor of engineering product development at SUTD, explained in a press statement.
As a demonstration of their concept, Yang and his colleagues crafted a nanoscopic replica of Wakayama prefecture’s mascot, Kii-chan. Tomohiro Mori, the lead author on the research paper, elucidated, “The complex geometry of the mascot—with its numerous curves, bumps, and dips—was an ideal model to demonstrate the efficacy of our technique. Bright prospects of achieving uniform shrinkage for any model, regardless of its shape or the platform solidity, are indicated by the successful shrinkage of such a detailed model.”
One of the most fascinating uses of TPL enhancing this new method involves the creation of chromaphores – molecules that react to various light frequencies. This could assist in the development of materials engineered to respond to specific lighting conditions. “This is practically applicable in anti-counterfeiting, allowing for item authentication through unique structural colors and the emission characteristics of these materials,” Yang elaborated.
From an industrial perspective, this unique TPL method can be utilized to produce new heatsinks for CPUs and GPUs, as well as compact mechanical components featuring intricate geometries, optical elements capable of manipulating light, and acoustic devices for more precise sound control.
Continue reading this story on ENGINEERING.com
“Why did the 3D printer go to therapy? Because it had too many layers of unresolved issues!”
0 Comments