The study of the effect of microcontrations in the separation of blood cells: soft lithography and micromilling

• Autor(a) principal: Lopes, Ana Raquel Jácome
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10198/11595
• topic: Biomedical devices; Lab-on-chips; Micromilling; Lithography; Cell free layer

The detection, separation and manipulation of microparticles and blood cells are important stages for biologic and chemical analysis. A new application in the area of Biomedical Engineering with potential is the development of portables micro devices for diagnostic, those are known as lab-on-chips or blood-on-chips. Their principal function is the separation and identification pathological cells in a blood sample. For example, infected cells with diabetes and malaria, present different deformation indices from healthy ones. This device should be a simple and low cost way to separate pathologic cells from healthy. The goal of this work is to design a geometry containing a microcontraction and test its effect in the cell free layer (CFL) and consequently in the separation of cells from plasma. In a first phase, it is used a soft lithography method for the fabrication of hyperbolic microchannels in PDMS. The hyperbolic microchannels are tested with a hematocrit of 5% of ovine red blood cells. Some results were presented and discussed. A low cost fabrication method was used, consisting in using a micromilling machine to mill in PMMA glass or Plexiglass to fabricate microchannels with simple contractions. The microchannels were tested with 5% of ovine red blood cells. The low cost method was discussed and some results about cell separation were presented.