About the Project
Can a robot weaken the soil in front of it without losing the grip that drives it forward? Bio-inspired burrowing systems could enable mobile, low-disturbance investigation of the shallow subsurface, reaching locations that are difficult to access using drilling, trenching or conventional vertical probes. However, most current knowledge comes from controlled, homogeneous granular materials. The behaviour of burrowing systems in partially saturated, layered and spatially variable ground remains…
poorly understood.
Burrowing presents a fundamental soil-mechanics challenge. The advancing part of a robot requires low soil resistance, while its anchor must generate sufficient reaction force to prevent backward movement. Razor clams manage this competing requirement by localising fluidisation around the moving region while the foot extends and anchors below, the disturbance decaying sharply with distance from the body. In partially saturated soil, local wetting changes suction, stress and interface resistance, potentially affecting both penetration and anchorage. Changes in soil density, grading or moisture may therefore cause transitions between successful advance, inefficient penetration and anchor slip.
This PhD will investigate the soil-mechanical processes governing these transitions. The student will:
- quantify how stress, suction and local wetting affect tip resistance and anchor capacity over repeated burrowing cycles;
- investigate how interfaces between soil layers of contrasting density, grading and moisture alter penetration and anchorage;
- develop particle-based and reduced-order models that predict burrowing behaviour in partially saturated, variable ground.
The research will combine physical experiments, advanced sensing and numerical modelling. The student will design and calibrate modular tip and anchor components instrumented for force, displacement, tactile-pressure and distributed fibre-optic measurements. Tests will progress from separate penetration and anchor-expansion experiments to mechanically simplified burrowing cycles across prepared soil interfaces in an existing soil chamber.
Discrete-element method simulations incorporating capillary interactions will be calibrated and validated against the experiments. The resulting evidence and models will produce burrowing-regime maps, interface-crossing criteria and design guidance for future stress-aware robotic probes. The student will graduate with a rare combination of experimental geomechanics, instrumentation and numerical modelling.
Supervision spans geotechnical engineering and sensing (Dr Xiaomin Xu), robotics and mechatronics (Prof Andrew Weightman) and computational modelling (Dr Junlong Shang). A2 Advanced Monitoring, an industrial collaborator, will contribute specialist distributed fibre-optic equipment, sensing materials, technical training and support with data interpretation.
The project will provide training in unsaturated-soil mechanics, physical modelling, instrumentation, mechanical design, distributed fibre-optic sensing, programming and discrete-element modelling. It is suitable for applicants from civil, geotechnical or mechanical engineering, robotics, applied mechanics or a closely related discipline who are interested in combining laboratory experimentation with computational analysis. The findings will support future ground-investigation, geohazard-monitoring and subsurface-robotics technologies, and the same framework underpins low-mass probes for planetary regolith, where reaction force is similarly scarce.
This project is expected to start in September 2027.
Before you apply: We strongly recommend that you contact the supervisors for this project before you apply.
How to apply: To be considered for this project you must complete a formal application through our online application portal. If you already have an applicant account this link will directly open an application for PhD School of Engineering Scholarships. If you don't already have an applicant account, please follow the instructions here.
When applying, please specify the full title and supervisor/s of the project, details of your previous study, and names and contact details of two referees. You must also upload a Supporting Statement describing the motivation to apply to the project, your CV and transcripts of awarded and in-progress university qualifications. Please note late or incomplete applications will not be considered.
Equality, diversity and inclusion are fundamental to the success of The University of Manchester and central to all our activities. A diverse research community strengthens creativity, productivity and quality, while increasing the societal and economic impact of our work. We welcome applicants from all career paths, backgrounds and sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation or transgender status.
We welcome applications from candidates returning to study after a career break or experience in other roles. Flexible study arrangements may be available, including part-time study at 50%, 60% or 80%, subject to the requirements of the project and funder.
Eligibility: The standard academic entry requirement for this PhD is an upper second-class (2:1) honours degree in a discipline directly relevant to the PhD such as civil or geotechnical engineering, mechanical engineering, robotics or mechatronics, applied mechanics, engineering mathematics (or international equivalent) OR any upper-second class (2:1) honours degree and a Master's degree at merit in a discipline directly relevant to the PhD such as civil or geotechnical engineering, mechanical engineering, robotics or mechatronics, applied mechanics, engineering mathematics (or international equivalent). The project is particularly suited to candidates interested in combining laboratory experimentation with computational modelling. Previous research experience in Python, C++ or MATLAB; and numerical modelling using discrete-element or finite-element methods is desirable.
This project will remain open until filled.
If your application is submitted by 1st November 2026, you can expect a decision by 18th December 2026.
If your application is submitted by 15th January 2027, you can expect a decision by 30th March 2027.
Self or externally funded students can also be considered for this project.
Funding Notes
Funding for this project covers tuition fees, UKRI minimum annual stipend (currently £21,805/annum) and up to a £2.5k/annum research training support grant for the full duration of the 3.5-year programme.