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Nanoscale forming and moulding

We perform both applied and fundamental research into moulding and forming operations, mostly on polymer systems. For example, we discovered polymer flow scaling violations in nanoscale moulding.  Isolation and instrumentation of model nanoscale polymer flows associated with nanoimprint lithography, a new industrial processing technique, led to the discovery of a complete inversion of the well-established viscosity to molecular weight scaling relation for entangled polymer melt flow when gaps sizes confine the polymer molecule below its radius of gyration.     The conventional scaling relationship, based on refinement to the predictions of the famous polymer reptation model of P. de Gennes, underpins understanding of major polymer manufacturing techniques such as injection moulding.   

These techniques are currently being applied in a roll-to-roll (R2R) format by our group to tissue scaffolding applications in conjunction with Trinity Biomedical Engineering and the Royal College of Surgeons Ireland. 

Key publications

Rowland, H. D., W. P. King, J. B. Pethica, and G. L. W. Cross, Molecular Confinement Accelerates Deformation of Entangled Polymers During Squeeze Flow, Science, 322, 720-724, (2008).

Self assembly and mechanics of 2D materials

Pleatronic systems

We are developing a new technlogy we call pleatronics which uses nanoscale optoelectromechanical pleat components based on a newly discovered behaviour of self-animated folding, tearing and sliding of molecularly thin, two dimensional material sheets like graphene.  Pleats comprise atomically smooth, flexible structural elements of attogram mass manipulated by configurable and reversible van der Waals and electrostatic forces.  These forces act under an unusual holonomic constraint:  They induce motion in the spatial manifold of a host sheet adhered to a surface of arbitrary macroscopic curvature. In addition, frictional waveguiding due to enforced atomic incommensurability ensures pleats attached to smooth substrates slide at high speed over long distances in an exotic, low friction state of superlubricity.  Self-assembling pleats are thus unique objects that offer a radical new approach to designing, building and actuating fast, high quality nanomechanical elements that are coupled to exceptional electronic and optical properties of 2D materials.  We aim to design and build novel nanoscale optoelectromechanical pleat elements such as resonant elements of oscillator circuits, plasmonic-tuned metamaterials manipulating mm wave-fronts, and fast switch arrays regulating reactant mass in micro-reactors or light transmission. 

Key publications:

Annett J., Cross, G. L. W., Self-assembly of graphene ribbons by spontaneous self-tearing and peeling from a substrate, Nature 535, 271-275, (2016).

Free volume engineering in non-equilibrium matter

Under construction

Diamond NEMS

Under construction

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