Additive manufacturing of micro-scale tensegrities
Ada Amendola and Fernando Fraternali, from the Department of Civil Engineering of the University of Salerno (Italy), and Howon Lee, from the Department of Mechanical Engineering of the Seoul National University (Korea) have developed in-house-built, projection micro-stereolitography (PμSL) systems  for the 3D printing of micro-scale tensegrity structures.
PμSL is an additive fabrication technique based on a photo polymerization reaction capable of generating complex three-dimensional structures across a range extending from micro- to small-scale. The additive manufacturing system uses a state-of-the-art digital micro-display as a dynamically reconfigurable photomask, which spatially modulates ultraviolet (UV) emitted from a high power light-emitting diode (LED). Liquid polymer resin is photo-chemically converted into a solid 3-D micro-structure in a layer-by-layer fashion. PμSL allows the use of swelling gels that can grow and shrink as a function of humidity and temperature . Once dried, these members contract, creating internal prestress.
Such a research generalizes a previous one dealing with the 3D printing of tensegrity structures through electron beam melting in Ti6Al4V titanium alloy, conducted by Amendola and Fraternali at the University of Salerno in collaboration with Russel Goodall and his research group at the Department of Materials Science and Engineering of the University of Sheffield (UK). Tensegrity structures 3D-printed with temporary supports have been post-tensioned employing Spectra fibers .
Making use of self-similarity concepts, bio-inspired design, and the highly nonlinear response of micro-scale tensegrity building blocks, this project aims at developing groundbreaking metamaterials for applications in structural engineering, robotics, impact protection, and sound focusing -.
 Han, D., Lee, H. et. al., 2019. Rapid multi-material 3D printing with projection micro-stereolithography using dynamic fluidic control. Addit. Manuf., 27, 606-615.
 Lee, H., Zhang, J., Jiang, H., Fang, N. X., 2012. Prescribed pattern transformation in swelling gel tubes by elastic instability. Phys. Rev. Lett., 108, 214304.
 Amendola, A., Nava, E.H., Goodall, R., Todd, I., Skelton, R.E., Fraternali, F., 2015. On the additive manufacturing and testing of tensegrity structures. Compos. Struct., 131, 66-71.
 Fraternali, F., Senatore, L. and Daraio, C., 2012. Solitary waves on tensegrity lattices. J Mech Phys Solids 60, 1137-1144.
 Fraternali, F., Carpentieri, G., Amendola, A., Skelton, R.E., Nesterenko, V. F., 2014. Multiscale tunability of solitary wave dynamics in tensegrity metamaterials. Appl Phys Lett, 105, 201903.
 Micheletti, A., Ruscica, G., Fraternali F., 2019. On the compact wave dynamics of tensegrity beams in multiple dimensions. Nonlinear Dynam., 98, 2737–2753.
 Vangelatos, Z.; Micheletti, A.; P. Grigoropoulos, C.; Fraternali, F., 2020. Design and testing of bistable lattices with tensegrity architecture and nanoscale features fabricated by multiphoton lithography. Nanomaterials, 10, 652.
The 2022 International Workshop on Multiscale Innovative Materials and Structures (MIMS22), was held in a scenic venue of the lovely village of Cetara along the Amalfi Coast (Salerno, Italy; September 29th – October 1st, 2022).
This was the 4th Edition of a fortunate series of Workshop aimed at collecting topnotch researchers working at the forefront of applied mechanics, material science and engineering, and physics to further our understanding of mechanics of materials at different scales, and its application to the design, modeling, manufacturing and experimentation of innovative multiscale materials and structures.
The Chairs of the Workshop are happy to announce that the final program of the Workshop is available at the webpage: https://www.multiscale.unisa.it/program. They wish to warmly thank the organizing secretariat for the excellent job done in managing two full days of exciting lectures, which were given in spectacular conference rooms facing the gulf of Salerno.
A special issue of Mechanics Research Communications (MRC) will collect original, peer-reviewed contributions presented at the Workshop. The submission deadline is 30 November 2022. The Guest Editors and the submission procedures are provided below.
Professor Fernando Fraternali, University of Salerno
Professor Sébastien Guenneau, Imperial College London, CNRS
Professor Muamer Kadic, FEMTO-ST Institute
Professor Anthony Rosato, New Jersey Institute of Technology
The submission website is available at: https://www.editorialmanager.com/mrc/default1.aspx.To ensure that all manuscripts are correctly identified for inclusion into the special issue you are editing, it is important that authors select SI: MIMS 2022 when they reach the “Article Type” step in the submission process.
Department of Civil Engineering
University of Salerno, Italy
Graeme W. Milton
Department of Mathematics
University of Utah, USA
Anthony D. Rosato
Department of Mechanical Engineering
New Jersey Institute of Technology, USA
We are happy to advertise a recent MOOC entitled “From seismology to earthquake engineering”, published by the group of Jean-François SEMBLAT from ENSTA Paris | Institut Polytechnique de Paris & IMSIA | Institute of Mechanical Sciences and Industrial Applications
It may be interesting for your students or your colleagues.
The teaser is available here:
and free enrollment is possible here:
So do not hesitate to share these links!
We are happy to advertise a recent paper on A biomimetic sliding–stretching approach to seismic isolation, which has been highlighted in Nature. The paper develops a novel seismic isolator that can be easily assembled in a fabrication lab using 3D-printed parts and metallic components. It mimics the mechanics of the human body through linkages that replicate the bones of human limbs and stretchable membrane/tendons. This biomimetic, sliding-stretching isolator can be scaled to seismically protect infrastructure, buildings, artworks and equipment with customized properties and sustainable materials.
A biomimetic sliding–stretching approach to seismic isolation (University of Salerno)
An array of unit cells of the stretching-sliding isolator forming a periodic metamaterial (University of Salerno)
European Conference on Acoustic & Mechanical Metamaterials
The conference covers fundamental and industrial activities of acoustic and mechanical metamaterials ranging from applied mathematics and theoretical mechanics to more applied researches in control of vibrations, from low (seismic) to high (ultrasonic) frequencies.