Optical Fabrication and Imaging Facility for three-dimensional sub-micron designer materials for bioengineering and photonics

We propose a facility for 3D optical fabrication and imaging of nanomaterials, with applications in photonics and biomaterials. The facility will combine sub-micron fabrication of arbitrary shapes via a fast direct laserwriter and 3D microscopy of metal nanoparticles (or other light-scattering objects) within a material or biological tissue. Both the laserwriter and the microscope will be unique in the UK. The combination of 3D fabrication and imaging will generate applications in photonic materials, biomedical nanotechnology and tissue engineering, with spinout benefits across the full range of modern materials science.

To date, the great majority of modern nanofabrication and imaging techniques are limited to two dimensions. Much is to be gained from extending capabilities into the third dimension. In photonics for example, the full vectorial character of light could be exploited, enabling unprecedented control over the propagation and storage of light with three-dimensional nanostructured materials, metamaterials. Here, designs for new types of filters, energy concentrators, and light sources exist on the drawing board, but have thus far not been realized due to absence of reliable and rapid fabrication, and quality assessment using 3D imaging.

In the biological and biomaterials sciences, 3D images from confocal fluorescence microscopy have revolutionized our knowledge. However this approach cannot be applied to imaging non-fluorescent objects such as metal nanoparticles. The interactions of nanoparticles with biological tissue are becoming increasingly important from an environmental health perspective as nanoparticles find increasing use in consumer products. There is also the exciting prospect of using nanoparticles for therapeutic and diagnostic applications in clinical applications. For both these purposes, 3D imaging of nanoparticle cell interactions is required. Combining this approach with 3D fabrication of engineered scaffolds that combine with cells to form model tissues will generate improved in vitro assays for nanoparticle toxicology and the testing of nanotherapeutics, leading to improvements in human health and reducing the requirements for animal experiments.

Beyond the immediate impact for fundamental science outlined in the academic beneficiaries section, we expect 3D nanostructured materials to have a real impact on the economy on a < 5 year timescale.

For photonics, this immediate impact will include novel devices for optical filters and modulators exploiting highly chiral structures, compact laser light sources with a tailored emission profile, and structures for broadband field enhanced spectroscopy of trace gases and molecules. Three-dimensional structuring will enable a stronger interaction between the photonic material and for example optical gain materials, a prerequisite for translating many exciting concepts for active metamaterials from the drawing board into real devices. Here, as the centre of excellence and birthplace for metamaterials, we are ideally placed for generating impact both via our exceptional presence at international conferences, and our links to major industrial players in this field in the UK, particularly BAE Systems and dstl.

In the biomaterials and biomedicine fields, the facility will generate impact in tissue engineering, nanotoxicology and targeted delivery of therapeutic and diagnostic nanoparticles. The importance of both these fields is rapidly increasing, with manufactured nanoparticles playing an increasing role in consumer products and pioneering nanotherapeutics beginning to receive regulatory approval. An area of particular interest is the development of new in vitro assays of nanoparticle bioactivity, which combine the fabrication of scaffolds that model parts of tissues with dynamic 3D imaging of nanoparticle-cell interactions. In nanotoxicology, such simulated tissues will be used to evaluate harmful effects of environmental exposure to manufactured nanoparticles, and we have identified Prof. Kian Fan as a clinical Key User with whom we will trial this concept in models of the lung. A similar approach will enable more realistic in vitro testing of candidate nanoscale therapeutic and diagnostic agents, with Prof. David Dexter as a clinical Key User of this approach in the context of Parkinsons disease. In the long term such tissue engineered assays have the potential to not only benefit human health but also reduce the requirement for animal experiments. This has already been seen in cosmetics safety testing where assays based on tissue engineered skin are approved. To drive applications in nanoparticle diagnostics and especially SERS, Prof. Duncan Graham will act a Key User with extensive experience of science and commercialisation in this area. 3D fabrication will also have direct impact in tissue engineering and the generation of 3D culture environments for cellular therapies. The ability to generate arbitrary shapes in 3D will supersede a wide range of ad hoc techniques that are currently used to fabricate scaffolds of particular geometries for tissue replacement. Fabricated model tissues will also find applications as culture environments, for example in adoptive immunotherapies where immune cells are grown outside the body before being returned to treat disease.

Additional impact will arise from the training of PhD students and postdocs on this world-class equipment, giving UK employers access to expertise in advanced fabrication and imaging. This is particularly true given that both proposed intruments are unique in the UK. Furthermore the combined system will enable a variety of exciting MSc and MRes projects for students in Optics, Physics Materials and Biomedical Engineering.