The research area of porous materials is extremely diverse, including inorganic materials, organic polymers, synthetic frameworks, biological tissues and composite systems. The variety of applications is equally wide ranging, including renewable energy, separation processes, carbon capture, catalysis, water purification, electronic materials and medicine. This requires combined expertise across multiple science and engineering disciplines, and access to specialist characterisation facilities to study both pore sizes and phenomena that can span multiple scales. A single institution cannot cover the full range of expertise, facilities and applications and a combined effort is therefore required. The EPSRC Network in Engineering Porous Materials at Multiple Scales (EPoMM) therefore aims to foster multiscale and applications- led collaboration between scientists and engineers that spans the entire engineering and physical sciences portfolio. These collaborations will inspire new research directions and new applications to achieve globally significant outcomes with academic, commercial and societal benefits. The vision of the ESPRC Network for Engineering Porous Materials at Multiple Scales (EPoMM) is to make the UK an internationally recognised beacon for multiscale porous materials research, where new collaborations are formed, new research directions are identified, expert advice can be sought, and innovations are commercialised.

Augmented reality (AR) has the power to seamlessly integrate the digital world with physical reality. It could provide surgeons with vital medical data as they operate, allow athletes to access training information seamlessly whilst playing sports and offers countless other opportunities in business, leisure and beyond. However, currently AR technologies are let down by the performance of microdisplays. AR devices must operate successfully not only in darkened rooms but also in bright sunlight, and must also be very small and run all day on one charge of a compact battery. Hence, enormous demands are placed on tiny light emitters in microdisplays in terms of brightness and efficiency. For AR to become a mass market technology, any new approach to microdisplays will need to not only meet these demands, but also allow easy manufacturing. Current light emitting diodes (LEDs) fail to meet these needs, since key materials which work well for larger area light emitters exhibit a drop in efficiency when the device size is shrunk to meet the demands of form factor and resolution imposed by AR. However, in terms of large scale LEDs, devices based on gallium nitride (GaN) have been tremendously successful, transforming the lighting industry. GaN LEDs also show much lower drops in efficiency with reduction in size than other similar materials. Unfortunately, these GaN LEDs are highly efficient only for light emission in the blue region of the spectrum. Green, amber and particularly red devices based on the same materials have much lower efficiencies, but are needed to create full colour microdisplays. In white LED light bulbs, blue light is converted to other colours by phosphor materials, but these phosphors are manufactured as bulky micron sized powders, too coarse to be used in microLEDs. In this project, we will take a new approach to integrating alternative, nanometre-scale phosphor particles (ca. 100 atoms wide) with nitride LEDs. Our alternative phosphors are highly luminescent colloidal nanoparticles, synthesised straightforwardly in solution using scalable techniques and easily made into nanoparticle inks. These materials are already used in "QLED" display technologies, but display manufacture is complex and the difficulties increase substantially as the device shrinks. Our new concept is to use printing technologies to inject nanoparticles not onto the surface of LEDs, but into nanoscale pores in the GaN itself. The nanoporous GaN materials are a very recent development and unique, scalable methods for their fabrication have been invented in our laboratory. By printing onto these porous scaffolds we will exploit capillary action to suck the nanoparticles into the desired region of the device, preventing spreading of the nanoparticle ink and hence achieving controlled manufacture straightforwardly at the required scale. In so doing, we will create a new optical composite material - a combination of the GaN and the highly luminescent nanoparticles - and by using the structure of the nanopores to align and control the array of nanoparticles, we will enable new and more sophisticated devices, for future display technologies such as AR in three dimensions.