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Nsidibe-Obong Ekpe Moses

Developing a numerical model to improve prediction of the performance of hydrogels.

Email: n.e.moses2@ncl.ac.uk

Project title

Multiphysics model for simulation of the dynamics Of pH-sensitive chitosan-genipin hydrogels

Supervisors

Project description

Used in wound dressings, chitosan-genipin hydrogels are antimicrobial and hemostatic. We are developing a numerical model to predict the volume transition behaviour of such hydrogels. This behaviour is in response to changes in the pH of their environment.

Our research will improve the design and optimisation of biomedical devices made from these hydrogels. To do this, we need insight into the dynamics of volume transition in response to their environment. Experiments do not provide a broad understanding of interactions between the gel and its environment. Thus, there is a need for mathematical modelling.

The Poisson-Nernst-Planck (PNP) equation with mechanical deformations offers a mathematical model. It depicts interplay of chemo-electro-mechanical fields in a hydrogel exposed to an ionic environment.

This continuum model is not amenable to analytical solutions. Complex geometry makes the finite difference method unsuitable for numerical simulation. Thus, we use a finite element method to develop a numerical model in COMSOL Multiphysics software. The model simulates the swelling/shrinking behaviour of chitosan-genipin hydrogel. This behaviour is in response to variation in the surroundings.

Using Direct-PARADISO linear system solver, I coupled and solved:

  • the transport of diluted species interface – capturing the diffusion and migration of ions
  • the electrostatics interface under an AC/DC module – the Poisson equation
  • the solid mechanics interface, describing the deformation of the gel

I will validate the model by comparing the simulation results with experimental data generated by our research group.

Interests

Finite element modelling, modelling and simulation of biomedical devices, drug delivery, soft sensing.

Qualifications

  • BEng in Chemical Engineering
  • MEng in Chemical Engineering