Written by expert practitioners in the field, this guide explores nanoindentation focusing on biological applications. The first section presents basics of nanoindentation, including the background of contact mechanics underlying indentation technique and the instrumentation used to gather mechanical data. Covering the applications of this technique, the second section discusses various topics, such as mineralized and non-mineralized tissues, cells and membranes, and cutting-edge applications at the molecular level. Well-researched and indispensable, this volume highlights the current challenges in the field while providing insights into the future.
Congrats to Dan on publishing his first peer-reviewed journal article, from work done prior to joining us in the Oyen Lab at Cambridge University Engineering Dept. The paper is, “Restoration of compressive loading properties of lumbar discs with a nucleus implant—a finite element analysis study” and is available as a pdf ‘in press’ at The Spine Journal website.
Post-doctoral researcher Matteo Galli’s work on poroelastic indentation analysis, including nanoindentation analysis, has been published in CMES, Computer Modeling in Engineering and Sciences. The article appears in a special issue of CMES focussing on contact mechanics, and edited by Prof. Selvadurai of McGill University. The paper describes an algorithm for fast analysis of indentation curves, with output parameters including the hydraulic permeability. This work eliminates the need to run reverse-FE models of individual indentation creep load-time plots, and allows for permeability mapping in short time-frames along with modulus mapping. Further, a universal database serves materials with a wide range of material properties, and the utility of the method is demonstrated for materials with kPa (hydrogel) to GPa (bone) elastic modulus values.
Michelle and Tammy provided mechanical expertise, in the form of nanoindentation testing and analysis, for a collaboration with the group of Molly Stevens at Imperial College London, Dept. of Materials. The study examined, using a wide variety of characterization techniques, the bone-like material formed by embryonic stem cells, adult stem cells and differentiated osteoblast cells. Interestingly, the material created by the embryonic stem cells was least “bone-like” while the tissue produced by the adult cells was both bone-like and similar to the osteoblast-derived tissue. Mechanically, there was about an order of magnitude difference between the tissue types, with embryonic cell-derived tissue demonstrating significantly smaller stiffness values compared with the other two groups. A write-up of the study appears in Nature Reports Stem Cells and the paper appeared recently in Nature Materials.
Michelle was recently in Manchester, on a visit hosted by Brian Derby of the University of Manchester’s School of Materials. The visit round up is posted online on their group’s website: http://brianderby.co.uk/