Within the Applied Optics and Photonics Group at Heriot-Watt there is ongoing research focused on the manufacture of functionally graded shape memory alloys, using Laser Induced Forward Transfer (LIFT), a flexible “direct write” process that allows materials to be controllably deposited at the microscale. LIFT is driven by rapid laser heating (using nanosecond (or shorter) laser pulses to eject material from a thin film of donor material onto a support substrate. We have been exploiting this process to generate alloyed mixtures of metals, with a particular focus on shape memory alloys (SMAs). We plan to combine this with highly localised thermal tailoring of SMA material parameters. Our Functionally Graded LIFT (FG-LIFT) concept is to use laser pulses to sequentially “print” thin “sub-voxels” of alloy films onto a substrate, in order to construct voxels each consisting of a number of sub-voxel layers of slightly different composition. By altering the laser parameters, subsequent thermal treatment will be used to provide control of interdiffusion within and between voxels providing very tight localised control of composition. 3D microstructures will hence be constructed by continuing to add additional voxels.
The overall aim is to develop a novel manufacturing process suitable for a new generation of instruments for microsurgery i.e. devices that can manipulate, grasp and cut inside the human body at a scale not currently possible.
The PhD student appointed will initially work alongside an established researcher, who is focused on the development of a process that incorporates sufficient control for generating tailored shape memory alloy layers. The student will then investigate approaches to scaling up the process to fabricate exemplar actuation components. The project will include the use of various short pulsed high power lasers and materials analysis using optical and scanning electron microscopes, x-ray diffraction (XRD) and Energy Dispersive X-ray analysis (EDX).
The PhD student appointed will be supported by a multi-disciplinary research team, including the supervision of Prof Duncan Hand, Dr Yuhang Chen and Prof Bob Reuben. Prof Hand’s expertise is in micro-manufacturing processes, many of which are laser-based, whilst Dr Chen’s expertise includes the application of computational mechanics to the design and optimisation of medical devices and mechanical characterisation of biological tissue and biomaterials. Prof Reuben provides expertise in materials and in engineering of bio-medical micro-mechanical devices.
Funding sources: this PhD position is eligible for funding from either the EPSRC Doctoral Training Partnership (DTP) or James Watt Scholarship (JWS) schemes.
Continue with Facebook
