Innovations in science and engineering lead to 3D-printed latex rubber breakthrough
written by Andrew Tie for Virginia Tech
Virginia Tech researchers have discovered a novel process to 3D-print latex rubber , unlocking the ability to print a variety of elastic materials with complex geometric shapes .
Latex , commonly known as the material in gloves or paint , refers to a group of polymers — long , repeating chains of molecules — coiled inside nanoparticles dispersed in water . 3D-printed latex and other similarly rubbery materials called elastomers could be used for a variety of applications , including soft robotics , medical devices , or shock absorbers .
3D-printed latex has been documented only a handful of times in scientific literature . None of the previous examples come close to the mechanical properties of the latex printed by an interdisciplinary team affiliated with the Macromolecules Innovation Institute ( MII ), the College of Science , and the College of Engineering .
An interdisciplinary group of chemistry and mechanical engineering researchers developed a novel process to 3D print latex rubber . Latex rubber parts , such as this impeller printed at 100 micron resolution , allow nondestructive reuse of complex molds because the parts exhibit a unique combination of flexibility and toughness .
Through novel innovations in both the chemistry and mechanical engineering disciplines , the team overcame some long-standing limitations of 3D-printing , also known as additive manufacturing . The researchers chemically modified liquid latexes to make them printable and built a custom 3D-printer with an embedded computer vision system to print accurate , high-resolution features of this high-performance material .
“ This project represents the quintessential example of interdisciplinary research ,” said Timothy Long , a professor of chemistry and a co-principal investigator on this project along with Christopher Williams , the L . S . Randolph Professor of mechanical engineering and interim director of MII . “ Neither of our labs would be able to accomplish this without the other .”
This project is a joint collaboration between Virginia Tech and Michelin North America via a National Science Foundation award aligned with the Grant Opportunities for Academic Liaison with Industry program , which supports teamed research between academia and industry . Details of their initial results are detailed in a journal article published in ACS Applied Materials & Interfaces .
Novel materials development in science
After unsuccessful attempts to synthesize a material that would provide the ideal molecular weight and mechanical properties , Phil Scott , a fifth-year macromolecular science and engineering student in the Long Research Group , turned to commercial liquid latexes .
The researchers ultimately wanted this material in a solid 3D-printed form , but Scott first needed to augment the chemical composition to allow it to print .
Scott ran into a fundamental challenge : liquid latex is extremely fragile and difficult for chemists to alter .
“ Latexes are in a state of zen ,” said Viswanath Meenakshisundaram , a fifth-year mechanical engineering Ph . D . student in the Design , Research , and Education for Additive Manufacturing Systems Lab who collaborated with Scott . “ If you add anything to it , it ’ ll completely lose its stability and crash out .”
Then , the chemists came up with a new idea : What if Scott built a scaffold , similar to those used in building
24 RESEARCH • VIRGINIA TECH MECHANICAL ENGINEERING ANNUAL REPORT • 2019-2020