- Title
- Optimisation of the fabrication conditions and characterisation of polymer/OMMT composites microcantilevers
- Creator
- Cele, Hastings Mthobisi
- Subject
- Biopolymers, Polymeric composites, Biodegradable plastics
- Date
- 2015-11-10
- Type
- Thesis
- Identifier
- uj:14528
- Identifier
- http://hdl.handle.net/10210/15058
- Description
- PhD. (Applied Chemistry), This dissertation presents work involving novel fabrication conditions of polylactide (PLA) based microcantilevers (μCs) as well as the characterisation of the fabricated cantilever beams. Focused ion beam (FIB) milling and micro-injection moulding were chosen as the fabrication processes during this research. Unfortunately, FIB milling was a time-consuming fabrication technique and could not maintain the shape of the sample. Micro-injection moulding (μIM) was chosen as the main fabrication process of μCs because it is a commercially used technique and can produce many cantilevers per cycle. Before the fabrication of the actual cantilevers, deflection comparison of the two types of cantilevers (Si & polymer) was made using structural mechanics application mode of MEMS module of COMSOL Multiphysics. The simulations showed that polymer μC deflects more than Si μC because of its low Young’s modulus. Another modelling and simulation was made based on the Eigen frequencies of PLA and Si cantilevers with various geometries. The predictions of the modelled cantilever beams depicted that resonance frequency depends on the mechanical properties of the material as well dimensions of the beams. For μIM, a shim-stock mould can be used to produce μCs from a modified PLA extrusion grade.
- Contributor
- Sinha Ray, S. , Prof.
- Rights
- University of Johannesburg
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