Existing technologies rely on two-dimensional scanning of energy beams, an approach which limits system productivity and results in thermal gradients leading to residual stresses. This research project will focus on maximising builds rates and minimising thermal stresses by consolidating powder layers in a single exposure, initially focusing on the hemispherical structures commonly found in joint prostheses.
The project focuses on eliminating the anode’s contribution to outgassing and plasma formation caused by the near surface ionization of the outgassed neutral atoms by the desorbed electrons, thus increasing the lowest achievable pressure in vacuum electronics devices improving their efficiency.
The aim of this research project is the investigation of how cold spray, a process used to create metal coatings, can be applied to 3D structuring, and the development of a manufacturing process for the creation of bulk, high fidelity surfaces.
Developing in-situ monitoring, analysis and control systems for the floating catalyst carbon nanotube fibre production process - James Ryley
Since their discovery carbon nanotubes were expected to lead to the creation of next generation electrical and mechanical products due to their extreme properties, all while being composed of cheaply available carbon. In practice, while laboratory scale synthesis and chemistry has been widely explored bulk industrial production methods (low cost, high volume and scalable) have not caught up, partly due to the difficulty of translating individual nanotube properties to larger objects. The Macromolecular Materials Laboratory here in Cambridge has been tackling this challenge for the past decade through the development of their unique floating catalyst technique. The single-step continuous process uses the thermal breakdown on iron, sulphur and carbon compounds to form entangled nanotube ‘smoke’ which is mechanically drawn down and wound to form a film or condensed to form a thread with excellent mechanical and electrical properties.
Development and optimisation of an optofluidic nano tweezers system for trapping nanometre crystals for synchrotron x-ray diffraction experiments - Alexandre Diaz
This project investigates optofluidic technology and evanescent field optical tweezing as more efficient and biologically compatible sample loading solution for micro and nano protein crystals, in synchrotron and free electron lasers (X-FELS) x-ray crystallography beamlines. The project is both sponsored and in collaboration with the Diamond light source national synchrotron.
Although conventional lithography methods can provide precisely located nano/micro patterning and cutting on graphene, it involves a long sequence of process operations, which may also increase the risk of contamination. Femtosecond laser micromachining has the potential for offering free-form post-patterning of general graphene devices with limited thermal effects, high processing speed and complex shapes.
This PhD project has been initiated to develop a laser-based precision additive manufacturing route for the CIM-UP platform at the University of Cambridge.
Additive Manufacturing (AM) applied to the production of metal components by the melting of metal powders rely on expensive and lengthy methods. Well established technologies using Electron Beam (EBM) and Selective Laser Melting (SLM) currently steer a single or a limited number of beams to raster scan a bed of powder. These methodologies are relatively slow and expensive compared to other manufacturing techniques, and have limitations regarding the output rate of powder melting. Even though they are continuously increasing their performance they still offer an increased throughput at a high cost requiring multi-stage processing
A main objective of the programme is to develop and implement a novel integrated plasma diagnostics tool by combining nN force measurements with high speed pulsed digital holography, laser-induced fluorescence and volumetric ion current analysis within a thermal vacuum chamber. The proposed system will be used to increase our understanding of new and existing energy transfer mechanisms where plasmas are concerned e.g. studying phenomena in laser-matter interactions.
The central theme of this research project revolves around the development of low-friction and wear-resistant coatings deposited via SLD. The unique attributes of SLD allows for the deposition of thermally sensitive materials without altering the integrity and purity of the coating composition.
Ultrafast machining of high temperature superconductor nanostructures for novel mesoscale physics - Katjana Lange
High temperature superconductors (HTS) are novel materials that exhibit zero electrical resistance and exclusion of magnetic fields at temperatures over 77 K. The main aim of this project is to enhance the critical current density (Jc) of thin-film HTS bridges by creating edge-barrier pinning. Assuming a perfect edge, edge-barrier pinning effects bridges as large as 200 μm. This limit becomes smaller as edge quality degrades. Unlike photolithography, laser machining is a chemical free, flexible process; the use of an ultrafast laser gives minimal edge damage.
The integration of ultrafast lasers with metrology systems allows for closed-loop machining to occur. This allows for a sample of unknown properties to be taken inspected, machined, evaluated, and corrected in a single process which increase precision and reduces manufacturing time.