Sharif Digital Repository

Nowadays, due to the growing need of the human to further improve the health of the community, research in the field of pharmacology as well as simulation of the cell culture environment is increasing. One of the most important requirements for simulating cell culture is the use of concentration gradient in culture media. The reason for this is the dependence of cellular activity on the presence of a gradient of concentration in the environment. Also, in drug investigations, in order to speed up the examination of different drugs and reduce the amount of drug that will used, different concentrations of the drug should be considered simultaneously in the microchips. Therefore, to make the... 

In this project single sided dye sensitized solar cell is introduced as a new design that has both of electrodes in one side. These electrodes can be separated vertically by a thin insulator layer such as SiO2 or horizontally by lithographic method. First a metallic thin film is patterned by lithography, and then thickened by electrochemical deposition of Chromium. Platinum is electrodeposited on the substrate of counter electrode and a thin spacer layer is deposited on Platinum layer to separate it from Titanium dioxide layer.
In Chapters 1, 2 & 3 basic science and methods which are needed for doing this project is introduced. In chapter 1 material for making a standard dye sensitized... 

Micro-robotics is one of the currently emerging technologies which has attracted attentions for its probable applications in different fields including biotechnology, diagnosis and treatment in medical engineering as well as general studies in micro-scale science and engineering. Magnetic micro-robotics is considered as the most promising group, primarily due to the biocompatibility of magnetic fields and advances in electronic circuits to produce and control such fields. One critical point in utilizing these robots is their high density in comparison with the working fluid and their tendency to sink. In this thesis, a method to fabricate buoyant magnetic robots has been proposed based on... 

Nowadays, we are witnesses of deaths caused by cancer in large statistical amounts. Vast number of investigations are conducted for anticancer drug evaluation on human and animal cells using traditional two-dimensional and three-dimensional culturing platforms. However, most of them are not successful due to the lack of in-vivo relevant microenvironment in these platforms. One of the best cancer in-vitro cultures is the tumor spheroid which is a spherical cellular aggregation. By culturing these tumor spheroids in a microfluidic chip, it is possible to mimic the in-vivo microenvironment elements such as nutrient and metabolite gradients. Here we present a microfluidic device fabricated using... 

In this research we focus on fabrication, characterization and performance of biosensors based on vertically aligned carbon nanotubes. Carbon nanotubes have been used as high density carbon nanotubes and nanoelectrode array. Carbon nanotubes have been grown using plasma enhanced chemical vapor deposition method. Characterization and performance of biosensors have been studied by cyclic voltammetry and electrochemical impedance spectroscopy methods.
The mediator-less glutamate biosensor is prepared based on covalently attached glutamate dehydrogenase on vertically aligned carbon nanotubes. The biosensor has a low detection limit of 57 nM, two linear range of 0.1-20 µM with sensitivity of...