November AMP_Digital

1 0 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 | N O V E M B E R / D E C E M B E R 2 0 1 9 give more control over how the cracks form. Potential damage could avoid critical areas of flexible electronics, for instance, increasing its functional lifespan. What’s particularly important, the researchers say, is having PDMS as the basis for the flexible membrane, since it is known for its wide variety of uses. The study also integrates other com- mon materials. Through ongoing research on human skin, the team realized that the outermost layer—known as the stra- tum corneum—exhibits a network of V-shaped topographical microchannels that appear to be capable of guiding fractures to the skin. This study began with the idea of recreating this effect in nonbiological materials. Previous attempts to direct microcracks have utilized more solid means, such as copper films around TESTING | CHARACTERIZATION NEW SUPER MATERIAL TAKES ON BULLETS In a partnership between Aarhus University, Denmark, and the Univer- sity of Cambridge, U.K., researchers have established guidelines and failure maps for use of a lightweight, super- plastic material in joints with steel bolts. Commercially known as Dyneema or Spectra, the ultra-high molecular weight polyethylene (UHMWPE) mate- rial is quickly superseding the para- aramid fibrous material, Kevlar, for use in bullet-proof jackets. Demand exists for this super material in several other applications. The UHMWPE material consists of long chains of polyethylene, which AMETEK, Inc., Berwyn, Pa., will acquire Gatan, Pleasanton, Calif., a man- ufacturer of instrumentation and software used to enhance the operation and performance of electron microscopes, from Roper Technologies, Inc., Lakewood Ranch, Fla., for approximately $925 million. Gatan is a pioneer in direct detection technology for electron microscopy. Its prod- uct portfolio includes electron microscopy cameras and instrumentation, electron energy filters, software, and accessories. ametek.com , gatan. com, ropertech.com . BRIEFS Verder Scientific, Newton, Pa., is looking for strategic investments, creating stable, highly competitive instrument business companies focusing on niche markets. EZ- mat is a distributor of materials testing equipment in China and currently represents two of the Verder Scientific product lines for metallographic preparation and hardness testing—ATM and Qness. verder-scientific.com, ez-mat.com. strengthen the intermolecular inter- actions of the substance and enable the material to transfer stress loads effec- tively to the polymer skeleton. This means that UHMWPE fibers have an incredibly high tensile strength compared to many other thermoplas- tics and also implies that the material is much stronger than steel in its fiber direction. The tensile strength of high- strength steel is approximately 900 MPa, but 3000 MPa would be required to break the fibers in UHMWPE. The new research results are favorable for the commercial use of UHMWPE, which is being increasingly introduced in the shipping industry’s containers, ropes, and nets, as well as armor for vehicles and personnel and in the textile industry. www.international. au.dk , www.international.au.dk . AVOIDING CRITICAL FAILURES IN BIOMEDICAL DEVICES A research team from Binghamton University, N.Y., is using the topography of human skin as a model—not for pre- venting cracks but for directing them in the best way possible to avoid fail- ures in critical components and make repairs easier. The Binghamton research team engineered a series of single-layer and dual-layer membranes from silicone- based polydimethylsiloxane (PDMS), an inert and nontoxic material used in bio- medical research. Embedded into the layers are minuscule channels meant to guide any cracks that form which, as part of a biomedical device, would The fibers of this UHMWPE test subject failed to break after numerous attempts at deformation. Courtesy of Simon Skovgård. Associate professor of biomedical engineering, Guy German, aims to replicate the flexibility of human skin in nonbiological materials. Courtesy of Binghamton University, State University of New York.