May/June_AMP_Digital

6 A D V A N C E D M A T E R I A L S & P R O C E S S E S | M A Y / J U N E 2 0 2 0 AS SEEN ON ASM CONNECT Here are excerpts of recent posts on the member discussion board, ASM Connect. To join in the discussions or start a new thread, log on to www. connect.asminternational.org . MATERIALS CONSIDERATIONS IN REDUCING VIRUS TRANSMISSIONS Traditionally, in Bengal (India) we used to use copper and brass glasses, plates, jugs, and other vessels [until the] fifties. Also all Hindu puja utensils, lamps, etc. are made from copper or brass. In India, copper or copper-plated utensils for regular use are coming back again. Biomedical material research is mostly confined to developing differ- ent implants. It may be worthwhile to research the reactions of materials to virus. Ram Chattopadhyay The ASM Headquarters design in- cludes many interesting uses of differ- ent metals, including brass handrails on the “floating staircase” in the cen- ter of the building. I always thought the choice of brass was made for aesthetic reasons, but perhaps the antimicrobial properties were also a consideration. Scott Henry I remember a few years ago a set of very interesting research using tex- turing to prevent bacterial adhesion to surfaces. It was pretty much insensi- tive to what the surface was made from (many chose stainless steel for cleaning purposes). It worked by using unfavor- able topography to prevent the bacte- ria from adhering, and thus surviving. I like to think it annoyed the bacteria to death. I have not heard if such a surface profile control approach could be used for COVID-19 virus, does anyone know if it would be possible? E-coli is 25 µm diameter, and COVID-19 is only 0.12 µm diameter, but if the texturing works by creating super-hydrophobicity, then perhaps it could still work for a virus? Bradley Crannell Our teamhas recently filed a provi- sional patent describing the use of cop- per-precipitation-strengthened steels for applications as antimicrobial touch surfaces. These steels were originally developed for bridges because of their excellent strength-toughness-weather- ing resistance combination. It dawned on us that the nanometer-sized cop- per precipitates can exhibit similar anti- microbial properties as copper or cop- per-rich alloys. Even at a few wt.% cop- per concentration, the steels deactivate E. coli in less than 30 minutes just like pure copper. The surface chemistry lit- erature indicates that chemical reactiv- ity can be size-dependent. We suspect that on a per atom basis, nanometer- sized copper may have enhanced an- timicrobial potency than pure copper. Perhaps materials scientists and engi- neers can do something about these nasty coronaviruses! Yip-wah Chung, FASM Editor’s note: See “Can Copper Help Fight COVID-19?” on page 21 in this issue for more discussion. VENTILATOR MATERIALS OF CONSTRUCTION With the current COVID-19 situa- tion does anyone have a good link or is knowledgeable about requirements or approved materials used in medical ventilator designs? I was able to find the attached link that describes “Basic Principles of Ven- tilator Design” [via accessmedicine. mhmedical.com ]. It describes various designs, no details about materials of construction, but highlights electron- ic monitoring and control and valves. The ventilator systems are pretty com- plex therefore reliability of the compo- nents and materials of construction are apparently important. Don Hashiguchi, FASM FEEDBACK We welcome all comments and suggestions. Send letters to joanne.miller@asminternational.org . These miniaturized super magnets were produced using laser-based 3D printing. Courtesy of TU Graz. FIRST 3D-PRINTED NEO MAGNET I enjoy reading AM&P. It is very well presented and a joy to read and learn. In the recent February/March issue [page 64] you cited work on NdFeB 3D printing from Austria. Good one. However, the first 3D printing of neo magnets was done by a group from ABB Switzerland, attached is the publication [“Net Shape 3D Printed NdFeB Permanent Magnet,” ABB Corporate Research Center, Adv. Eng. Mater., 19(8), 2017]. 3D-printed neo magnets exhibited unique characteristics suggesting self-as- sembly. You can contact Jacim Jacimovic for more details. Dr. Sim Narasimhan, FASM Antimicrobial door handles cast by Franklin Bronze Precision Components using EcoBrass C87850, a lead-free brass alloy designated and registered by the Federal EPA to be antimicrobial.