Porous Systems for Super Dense Memories and Sensor Applications

This project was dedicated to solving basic scientific issues and developing the scientific basis that underlies the improvement of super-dense memories, towards the terabit per square inch goal and the engineering of chemical and biological sensors. Both applications rely on porous materials among which porous alumina is the most promising. The research under this project in each of the objectives has lead to major advances. We have improved considerably the size distribution of the porous alumina used for masks using a double anodization process. We have also developed an unconventional “bootstrapping” method, which uses self-supporting porous membranes. This allowed fabrication and research on the properties of very well ordered array of small magnetic nanodots on different substrates, which could not be done otherwise. It also permitted us to develop new concepts of storage and explore the interaction between magnetic dots. Due to this technology we had also several major advances in the field of DNA sequencing and in the development of biosensors. This project leverages funding from AFOSR through extensive collaboration with colleagues at UC San Diego, UC Davis and Los Alamos National Labs and no cost, contribution of researchers that are spending extended periods of times at UCSD. EXECUTIVE SUMMARY This project was dedicated to solving basic scientific issues and developing the scientific basis that underlies the improvement of super-dense memories, towards the terabit per square inch goal and the engineering of chemical and biological sensors. Both applications rely on porous materials. Among them porous alumina has demonstrated to provide major improvements in these two diverse applications. At the beginning of this project we set the following objectives: a) to improve the geometry (regularity, shape, decreased size) of the pores, b) to fabricate and study the properties of nanostructured magnets in a variety of configurations and c) to apply this technology to chemical and biological sensing. These are forefront basic research topics and advances in them may lead to revolutionary changes in important technologies. This was already proven by earlier results from our group. The research under this project in each of the objectives has lead to major advances. We have improved considerably the size distribution of the porous alumina used for masks using a double anodization process. We have also developed an unconventional “bootstrapping” method, which uses self-supporting porous membranes. This new method allowed us to fabricate and investigate in detail the properties of very well ordered array of small magnetic nanodots on different substrates, which could not be done otherwise. It also permitted us to develop new concepts of storage and explore the interaction between magnetic dots. Due to this technology we had also several major advances in the field of DNA sequencing and in the development of biosensors. This project leverages funding from AFOSR through extensive collaboration with colleagues at UC San Diego, UC Davis and Los Alamos National Labs. This project also benefits from the, no cost, contribution of researchers that are spending extended periods of times at UCSD. Graduate students and postdoctoral fellows are intimately involved in every aspect of this research.