research

Polymer–metal–polymer composite films are widely used in packaging, building, and cooling, and more recently as envelopes for pouch lithium-ion batteries (LIBs). The influences of heat seal temperature and dwell time on the heat seal strength (HSS) of five different multilayer films were investigated by T-peel testing. The failure modes were observed and analyzed by digital optical microscopy. Heat-sealing temperature and dwell time interacted and simultaneously influenced the HSS. Temperature was confirmed as the primary factor while dwell time was secondary.

Transfer printing, an emerging manufacturing technique for heterogeneous material integration, is combined with the unique mechanics of soft composite films to realize a responsive surface for tunable topography in this work. Soft composite films are fabricated by transfer printing thin silicon ribbons on elastomeric films in a staggered manner. The corrugation formation in soft composite films requires a well-organized spatial distribution of the silicon ribbons which is enabled by transfer printing processes developed here.

cdmHUB has completed the level I micromechanics simulation challenge. Several micromechanics methods/tools including both commercially available tools such as  Altair MDS, ESI VPS, Digimat, SwiftComp and research codes such as MAC/GMC/HFGMC and FVDAM, are used to analyze six typical 2D/3D microstructures. All the results and model files, inputs and outputs, and the report are hosted on cdmHUB as a live project at https://cdmhub.org/projects/mmsimulationchalleng/.

In the attached paper we have shown that graphene and carbon nanotubes are in a self-stress state in their natural equilibrium state, that is, the state prior to the application of external loads. We have identified different sources of self-stresses and accurately evaluated them; we have shown that they are by no means negligible with respect to load-related nanostresses.

The performances of graphene sheet in micro- and nano-electronics and devices are significantly affected by its morphology, which depends on the surface features of the supporting substrate. The substrates with non-developable convex or concave surface are widely used with graphene sheet in applications but rarely studied. Therefore, theoretical models are established based on energy analysis to explain the adhesion mechanisms and predict the morphology of the monolayer graphene sheet on non-developable surface.