Join Us
We currently have a number of open research opportunities, as listed below. If you are interested or have any questions, please email any of our fantasic researchers: Professor Halina Rubinsztein-Dunlop, Dr Alexander Stilgoe, and Dr Timo Nieminen.
Summer/Winter Projects
The group frequently offers summer and winter projects as part of the UQ summer/winter research programs for UQ enrolled students. Details about the UQ summer/winter research program, including application dates, can be found on the UQ Website.
Capstone/Coursework Projects
Students may be able to get credit for working on a project with our group either as part of Physics Capstone, Fields in Physics or another eligible course. Interested students should first speak with their relevant course coordinator.
Internships/Volunteers
Students looking to gain experience using or simulating optical tweezers can volunteer with our group. If you are thinking you might like to do honours but can't decide on a project, this is a perfect opportunity to explore potential project opportunities before enrolling in honours.
UQ has the following scholarship options.
The group is currently offering the following honours and Internship projects:
Experimental projects
Control and measurement of optical active matter
Swarms of optically driven particles interact with each-other and their environment. Enquire about one of several projects that are aimed at revealing several aspects of the hidden inner workings of optical active matter.Probe microscopy for surface characterisation with optical tweezers
Brownian motion becomes a source of information, rather than a source of uncertainty. Weakly trapped optical probes enable the investigation of soft and deformable surfaces such as cells. Discover how random noise and a contact-free probe can tells us more about the world at the microscale.Thermal forces in optical tweezers
Brownian motion becomes a source of information, rather than a source of uncertainty. Weakly trapped optical probes enable the investigation of soft and deformable surfaces such as cells. Discover how random noise and a contact-free probe can tells us more about the world at the microscale.Bacteria trapping and study
General principles of motion, such as driving and resistive forces, and energy requirements, can be used study the scaling of the motion of organisms with size, fluid properties, etc. Such models can apply across many orders of magnitude of size, etc., from bacteria to macroscopic animals. Learn the physics of how small organisms explore and thrive in their enviornment.Momentum transfer in complex anisotropic optical materials
Optical tweezers operate our of linear optical momentum transfer in simple dielectric (non-conducting) materials. 21st century materials are more complex and can experience different electric and magnetic forces when scattering light that is shone from multiple directions. This project will investigate the prospects of either engineering a material or structuring light to improve light–matter interactions to create highly controlable high-pecision sensors.Remote surface characterisation
Remote sensing is an important technology used in surveying, construction, and other important applications. This project will test various kinds of projected visible and invisible light and measure the scattering from remote objects to determine feasibility as a future device.Computational and theory projects
Energy considerations in bacterial locomotion
General principles of motion, such as driving and resistive forces, and energy requirements, can be used study the scaling of the motion of organisms with size, fluid properties, etc. Such models can apply across many orders of magnitude of size, etc., from bacteria to macroscopic animals. Learn the physics of how small organisms explore and thrive in their enviornment.Single and multiple scattering and the Rayleigh hypothesis
There are a suite of methods to determine the scattering of small objects. The scattering of electromagnetic or other waves by particles typically involve representing the fields as sums or integrals. We would like to understand two important mathematical issues that are considered in these methods where there can be multiple particles. The first is how many terms are needed for accurate descriptions of scattering, the other is the choice of wavefunction which in some cases allow near fields to be directly expressed, but not for others. Some methods assume that the fields converge everywhere outside the scattering particle, even though such convergence is not guaranteed - this is the "Rayleigh hypothesis".Physical versus behavioural interactions in collective motion in active matter
Self-propelled active matter particles take energy from their environment and use it for motion and/or other purposes. Interaction between the active matter particles can result in collective motion such as flocking, schooling, and swarming, as seen with birds, fish, insects, and bacteria. The interactions can be behavioural ("Which way are my neighbours flying? How close are they?") or physical (e.g., bacteria). One important question is to what extent can artificial active matter particles, with purely physical interactions between them, mimic the complex collective motion driven by behaviour.Computational methods for multiple scattering
In principle, brute-force methods such as finite-difference time-domain (FDTD), the finite element method (FEM), and the discrete dipole approximation (DDA) allow us to computationally model multiple scattering problems. However, the computational demands of solving such problems for many particles can make them thoroughly infeasible. Methods making use of the single-scattering solutions for the individual particles can be much faster.We have several scholarships funded that are available for competitive applicants. Provided sufficient qualification and grade, these scholarships will cover your living expenses whilst you complete your degree. Generally, UQ has the following scholarship options.
The Optical Micromanipulation Group seeks to investigate the nature and applications of lights action on microscopic particles. We study all aspects of this diverse field from biophotonics applications such as studying wall effect in cells or manipulating micro-particles in-vivo; to creating new technologies such as optically driven micro-rotors. We are also interested in forces and torques created when light and mater interact at the nano-scale and how this interaction may be exploited to do cutting edge scientific research.
We currently have the following PhD projects available. In addition to the bellow projects, we often have other project ideas.
Students interested in attaining a PhD with any of the following projects should get in contact with us.
Experimental projects
Rotational optical active matter
The study of self-propelled active matter is a productive and dynamic multi-disciplinary field, and has led to greatly improved understanding of collective behaviour such as flocking, swarming, and even the behaviour of crowds during evacuation. Much of this work is centred on mathematical modelling due to difficulties in running controllable experiments due to potential logistic and other reasonable ethical restrictions. What is lacking in the great majority of such physical studies is the presence of complex long-range interactions, which can have surprising effects such as spontaneous ordering and synchronised collective motion. Our primary focus is to study physical systems of interacting self-propelled active matter. We will use camera tracking and optical tweezers to measure the interaction forces, and use optical and thermal forces to drive the active matter particles. Thus, we will better understand these subtle interactions, and will be able to use physically-measured parameters in computational modelling that will support our experimental study of active matter.Research area: Active matter
Advisor: Dr Alexander Stilgoe
Swimmers
Measure swimming forces of microorganisms/cells, including dependence on viscosity, nearby surfaces, nearby swimmers. Swimming forces in flow in microfluidic channels. Does the force depend on speed?Research area: Active matter
Advisor: Dr Timo Nieminen
Understanding active materials using advanced microscopy
Fundamental and simple principles of motion underly the movements of ordinary matter. The same is not true for active matter. Active matter is a broad category of particles (that can include living organisms too) that exhibit changes in behaviour depending on interactions with surrounding moving and stationary bodies. The behaviour of these systems cannot be derived from simple Newtonian laws. Many types of models have been proposed to investigate these systems. Verifying these models is challenging because accurate measurements of sufficiently complex systems are impossible with traditional tracking techniques. However, large amounts of microscopy data containing moving interacting bodies can be obtained. There are two goals: 1) Use new "big data" computational tracking tools based to filter and transform microscopy data into tracking information to analyse and compare with models and 2) to propose a new models of interacting swimming particles and investigate emergent phenomena such as the production of vortices within active matter.Research area: Microscopy
Advisor: Dr Alexander Stilgoe
3D Holographic microscope
Light-based microscopes have been at the forefront scientific research in the hard and soft physical sciences. They are limited by wave diffraction to resolutions of approximately half the wavelength of light used to image the sample. The image of this diffraction will change depending on the angle and wavelength of light used to illuminate the sample. Hence, these images contain complementary information about refractive index variation in 3D space. In this project we will advanced the field of microscopy by utilizing big data and machine learning to learn a filtering and transformation of data in a microscope system to yield synthetic images that accurately show the 3D localisation of refractive index variation within of complex environments. This will generate an unprecedented view of light-based microscope samples below the diffraction limit and into the intermediate scattering regime.Nano-thermodynamics of soft matter
Experimental measurements of Brownian motion in temperature gradients (how to make large temperature gradients without convective flow?), hot (cold?) Brownian motion. Microfabricated heat engines will be used to study enviroments where soft matter such as cells are found.Research area: Active matter
Advisor: Dr Timo Nieminen
Computational and theory projects
Classification of bacterial behaviour in optical tweezers using machine learning
Optical tweezers are a useful tool for studying small systems such as cells and micro-organisms. One application of optical tweezers is the study of micro-organisms which is of importance for understanding reproductive processes, diseases, and nano- and micro-fluid dynamics. Understanding what is going on when a particle is trapped by optical tweezers requires classification of the particle’s behaviour, such as classification of the different swimming behaviours. Certain behaviour can be determined by looking at the position or force frequency spectrum. This process can sometimes be time consuming and may not generalise well to different types of bacteria. A further difficulty is that these models sometimes rely on a previous prediction for the particle’s behaviour. This project will involve investigating how machine learning can be used to classify these different behaviour and explore how prior assumptions affect the generality and overall usefulness of the model.Research area: Active matter
Advisor: Dr Timo Nieminen
Solving electromagnetic scattering using deep neural nets
One of the most powerful techniques of getting useful particle scattering information from electromagnetic theory is the T-matrix method. Here we apply machine learning methods to solve boundary value problems in electromagnetic scattering. Machine learning techniques allow us to test a large parameter space of particles with many different geometries and composition out of approximate models. The outcome of this project is that it will solve one important outstanding problem in electromagnetic theory: How to efficiently solve electromagnetic scattering problems. These techniques have wide-reaching applications to photonics and the design of efficient photonic devices.Research area: Electromagnetic modelling
Advisor: Dr Alexander Stilgoe
Single and multiple scattering and the Rayleigh hypothesis
Hilbert space methods, such as the T-matrix method, for the scattering of electromagnetic or other waves by particles typically involve representing the fields as sums or integrals of a basis set of modes. Two mathematical issues need to be considered in these methods. First, the sum or integral over the of modes used is only guaranteed to converge to the fields in certain regions. For example, the scattered field represented in spherical wave modes is only guaranteed to converge outside the circumscribing sphere enclosing the scattering particle, and not between the circumscribing sphere and particle surface. Second, the infinite set of modes is truncated for practical computations, and might not converge subject to such truncation, even if convergence is guaranteed given infinite modes. Despite these two issues, the scattering problem can often be solved, giving a correct and convergence result for the far field. Some methods assume that the fields converge everywhere outside the scattering particle, even though such convergence is not guaranteed - this is the "Rayleigh hypothesis". Other methods will give essentially identical results in the far field without making such assumptions.Research area: Electromagnetic modelling
Advisor: Dr Timo Nieminen
Active matter with physical interactions in 1, 2, and 3D
Self-propelled active matter particles take energy from their environment and use it for motion and/or other purposes. Interaction between the active matter particles can result in collective motion such as flocking, schooling, and swarming, as seen with birds, fish, insects, and bacteria. The interactions can be behavioural ("Which way are my neighbours flying? How close are they?") or physical (e.g., bacteria). One important question is to what extent can artificial active matter particles, with purely physical interactions between them, mimic the complex collective motion driven by behaviour. Light can be uses as the energy source for artificial active matter particles, with optical and thermal forces producing motion. Interaction can be optical, hydrodynamic, or thermal.Research area: Active matter
Advisor: Dr Timo Nieminen
Nano-thermodynamics
Experimental measurements of Brownian motion in temperature gradients (how to make large temperature gradients without convective flow?), hot (cold?) Brownian motion. We would like to better understand how microfabricated heat engines will perform when used to study enviroments where soft matter such as cells are found.Research area: Active matter
Advisor: Dr Timo Nieminen
Prospective students with interests in these areas are encouraged to apply. Applicants should possess an appropriate qualification for entry into the PhD training scheme, and should have prior relevant research experience. Eligible students may be able to apply for funding to cover the cost of their research. For full details, see the UQ graduate school.
We are looking to hire talented postdoctoral researchers. If you are either someone who has submitted or recieved their PhD, we have grants that provide for postdoctoral researchers and are looking forward to hearing about what you can offer us in any of our research areas, found here!
Postdoctoral Fellowships are alsoavailable through a number of external and UQ schemes, including:
UQ Fellowships
This highly competitive annual round of fellowships offers three years of salary for research scientists at levels ranging from research fellow to full professor, depending on expertise. At research fellow level, preference is generally given to applicants external to UQ. The fellowships come, additionally, with a small amount of research funding.Our laboratory has historically been successful applying into this scheme. We are happy to assist qualified applicants in preparing a suitable application, provided we are contacted well in advance. For more information, refer to the UQ internal schemes page.
ARC Discovery Early Career Researcher Awards (DECRA)
The ARC Discovery Early Career Researcher Award (DECRA) scheme is a separate element of the Discovery Programme. The DECRA scheme will provide more focused support for researchers and create more opportunities for early-career researchers in both teaching and research, and research-only positions. It is anticipated that up to 200 three-year DECRAs, including up to $40,000 per annum in project funds, may be awarded each year. We are happy to assist qualified applicants in preparing a suitable application, provided we are contacted well in advance. For more information, refer to the UQ DECRA information page.