Supramolecular chemistry offers an exciting opportunity to assemble materials with molecular precision. However, there remains an unmet need to turn molecular self-assembly into functional materials and devices. Harnessing the inherent properties of both disordered proteins and graphene oxide (GO), we report a disordered protein-GO co-assembling system that through a diffusion-reaction process and disorder-to-order transitions generates hierarchically organized materials that exhibit high stability and access to non-equilibrium on demand. We use experimental approaches and molecular dynamics simulations to describe the underlying molecular mechanism of formation and establish key rules for its design and regulation. Through rapid prototyping techniques, we demonstrate the system’s capacity to be controlled with spatio-temporal precision into well-defined capillary-like fluidic microstructures with a high level of biocompatibility and, importantly, the capacity to withstand flow. Our study presents an innovative approach to transform rational supramolecular design into functional engineering with potential widespread use in microfluidic systems and organ-on-a-chip platforms.

Ethylene-propylene-diene terpolymer rubber (EPDM)-based nanocomposites containing carbon black (CB), graphite nanoplatelets (GNPs), and mixtures of the two fillers were prepared. The influence of the relative amounts of the two fillers on the dynamic and static friction coefficients was examined. The static analysis of the coefficient of friction suggests that the partial substitution GNPs into the EPDM/CB blend did not produce a significant variation of the surface grip. The sample comprising EPDM/CB composite and an effective amount of GNPs dispersed in the matrix provides an increase of the thermal conductivity, damping and mechanical properties of the nanocomposites. The morphological observations revealed that the replacement of CB with GNPs reduces the CB aggregation and, hence, improving the percolation of the hybrid fillers and the interface resistance of the composite. The development of thermally conducting elastomeric nanocomposites could envisage their utilization in the processing of rubber blends satisfying the increasing demand to reduce both the duration of the vulcanization process and thus the cost of the vulcanized rubbers.

We consider the mechanical motion of a system of six macroscopic pendula which are connected with springs and arranged in a hexagonal geometry. When the springs are pre-tensioned, the coupling between neighbouring pendula along the longitudinal (L) and the transverse (T) directions are different: identifying the motion along the L and T directions as the two components of a spin-like degree of freedom, we theoretically and experimentally verify that the pre-tensioned springs result in a tunable spin-orbit coupling. We elucidate the structure of such a spin-orbit coupling in the extended two-dimensional honeycomb lattice, making connections to physics of graphene. The experimental frequencies and the oscillation patterns of the eigenmodes for the hexagonal ring of pendula are extracted from a spectral analysis of the motion of the pendula in response to an external excitation and are found to be in good agreement with our theoretical predictions. We anticipate that extending this classical analogue of quantum mechanical spin-orbit coupling to two-dimensional lattices will lead to exciting new topological phenomena in classical mechanics. of a spin-orbit coupling for photons [26][27][28][29][30][31]. Spin-orbit coupling in such photonic systems has been predicted to induce various topological phenomena, such as topological phase transitions [31,32]. A detailed theoretical and experimental study of such a spin-orbit coupling for a hexagonal ring of exciton-polariton microcavities was reported in [30], where two polarisation states provided the pseudospin degrees of freedom.In the present work, we show that similar physics can be observed also in systems governed by Newtonian classical mechanics. Towards this goal, we theoretically and experimentally investigate an analogous mechanical model consisting of six pendula arranged in a hexagonal ring structure and coupled by springs. In particular, we observe that the frequency spectrum strongly depends on the ratio between the rest length of the springs and the equilibrium distance between neighbouring pendula. A mismatch between these two quantities results in a finite pre-tensioning of the springs which, as first anticipated by [33], is responsible for different effective spring constants along the longitudinal (L) and the transverse (T) directions with respect to the spring axis. This is analogous to how the coupling between neighbouring sites depends on the two polarisation states in the polariton lattice of [30]. On this basis, the mechanical system can also be interpreted as being subject to an effective spin-orbit coupling, as we show in the following.This article is organised as follows. In section 2 we introduce the mechanical system under consideration and we theoretically review the origin of the spin-orbit coupling term, first in an infinite honeycomb lattice, then in the hexagonal ring of pendula. For this latter case, we discuss in detail the oscillation eigenfrequencies and eigenmodes and we classify them in terms of the symmetry of the oscillation pattern...

Knots are fascinating topological elements, which can be found in both natural and artificial systems. While in most of the cases, knots cannot be loosened without breaking the strand where they are tightened, herein, attention is focused on slip or running knots, which on the contrary can be unfastened without compromising the structural integrity of their hosting material. Two different topologies are considered, involving opposite unfastening mechanisms, and their influence on the mechanical properties of natural fibers, as silkworm silk raw and degummed single fibers, is investigated and quantified. Slip knots with optimized shape and size result in a significant enhancement of fibers energy dissipation capability, up to 300–400%, without affecting their load bearing capacity.