PhD Scholarship
The University of Adelaide

School of Mathematical Sciences

Posted on: Tue Apr 11 2017

Micro-bubble and micro-bottle blowing in a fibre for whispering gallery resonator sensors.

This is an opportunity to work in the exciting area of optical fibre technology. You will work with Associate Professor Yvonne Stokes and members of the world-renowned Institute for Photonics and Advanced Sensing (IPAS) at the University of Adelaide. This is one of two PhD projects being offered; see also "Unsteady capillary stretching for microstructured tapers." Microstructured optical fibres (MOFs) have revolutionised optical fibre technology, with a virtually limitless range of designs for a wide range of applications, including as whispering gallery resonator biochemical sensors with the limit of detection potentially down to a single molecule. These are fabricated from commercially available capillaries by first drawing or tapering the capillary down to the required diameter (typically < 100μm), and then heating a small section while, at the same time, pressurising the air inside to form a bottle or bubble in the heated region. The thinner the wall of the micro-bubble/bottle the better the sensor, although some consideration has to be given to its fragility.

Mathematics is essential to solving the inverse problem of determining the preform and draw parameters to produce a desired fibre and has already proved to be of significant practical benefit. This project focuses on mathematical modelling of the fabrication of whispering gallery resonator sensors by blowing a micro-bubble or micro-bottle in a heated microstrutured taper. You will develop both flow and temperature models using asymptotic methods that exploit the slenderness and/or the small wall thickness of the taper. You will use your models to investigate the relationship between surface tension, pressure, wall thickness of the fibre/taper and wall thickness and size of the bubble/bottle. The thinner the wall of the fibre/taper the more sensitive it will be to the applied pressure and the greater the chance of blow-out and, consequently, failure to achieve the desired sensor. Avoiding this, while still achieving thin-walled micro-bubbles/bottles, will be of key interest. You will have the opportunity to be involved in experiments with skilled technicians, for comparison with your model predictions.


These include

  • A PhD scholarship of $26,682 per annum (2017 rate) for 3 years,
  • Full coverage of PhD tuition fees (if applicable),
  • Collaboration with experts in photonics at IPAS.


Applicants should hold a first class Honours or a Masters degree in applied mathematics, physics, engineering, or a closely related area, and should have some knowledge of theoretical fluid mechanics. Equivalent international qualifications will be considered.

For further information on the project or the application process please email Associate Professor Yvonne Stokes (

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