Progreso de la Investigacion

Hola a todos:

En esta entrada de mi blog voy a estar evaluando del progreso de las metas establecidas para este semestre. Se puede decir que he logrado al menos un 25% de mis metas lo que se puede catalogar como en la categoría 2. El estancamiento se debe a que en el procedimiento para mejorar la fabricaron de los micro-canales encontramos un problema con la parte de la alineación y es que al depositar el nuevo polímero las marcas hechas en el lift-off litography no pueden ser observadas con el SEM. Esto representa un gran problema debido a que el programa entonces no puede corregir el desfase que ocurre entre los segmentos del micro-canal. Ahora mismo me encuentro buscando información sobre el procedimiento para ver si otras personas han tenido el mismo problema. Por otra, parte la fabricación de las micro-cavidades para el estudio de neuronas va mas adelantada y ya entregamos las primeras fichas a los investigadores.

A continuación una copia del abstract de mi investigación.

Fabrication of biomedical devices by e-beam lithography

Biological research has always depended on engineering to provide the necessary mechanical and electrical devices to perform cutting edge procedures. This relationship has been so successful that new fields are being integrated into the equation. Nano-fabrication is one of those emerging fields and it is a technique that has been around for decades and it has left an amazing print in electronic devices and certainly will be a contributing factor for biomedical devices. Electron beam lithography (EBL) is one of the most common procedures used in nano-fabrication. EBL is the practice of exposing a surface covered with a photoresistive film to a beam of electrons following a predetermined pattern. The exposed area is usually removed in a developing procedure. This technique allows the fabrication of features at a nanometer scale.

Our goal is to employ EBL to fabricate micro and nano scale devices that serve as tools to study, manipulate, and sense biological cells and/or molecules. The fabrication of two types of devices has been the main focus of the current research project. The first device-type is designed to play a primary role in the improvement of the Raman signal in Raman Spectroscopy by the fabrication of homogenous geometric nano scale structures of known size and shape in silicon/polymethylmetacrylate (PMMA) substrates (Surface Enhanced Raman Spectroscopy or SERS). The second device-type is a system composed of microfabricated canals, patterned in glass/PMMA substrates, designed to study the biophysics and dynamics of neurons/neural network connections.

Preliminary structures have been fabricated for both of the device-types. For the silicon/PMMA device, hexagon and square structures of 100 nm in length and 50 nm in spacing between structures have been successfully fabricated. For the glass/PMMA device, arrays of linear, S shape and Y shapes cavities have been fabricated with dimension of approximately 50μm of length and 5μm wide. Details of the fabrication process and preliminary results of the Raman spectra enhancement will be presented.