The University of Maryland MRSEC grants ended in September 2013 after 17 years of successful operation. This site remains as a history of the center, but will not be actively maintained.

Undergraduate/Graduate Programs

2003 REU Projects

Interactions Between Biological Molecules and Magnetic Nanoparticles

The interactions between biological molecules and magnetic nanoparticles are being investigated because of the possibility of using the magnetic nanoparticles to handle the biological molecules to have medication delivered and to diagnose diverse sicknesses. To achieve this, we must find a way to mix them in a way that it doesn’t affect the biological molecules and cells and in a way in which they will target specific cells. In this investigation we look at how the magnetic nanoparticles interact with liquid crystals, which are the molecules that make up the walls of all living cells, and how once they are mixed we can use the nanoparticles to manipulate the liquid crystals. The mixtures are investigated first with a polarizing microscope to see how they align.

X-Ray Photoelectron Spectroscopy of Ultrathin Oxide Films

Ultrathin films of BiFeO₃ display both magnetic and ferroelectric properties that make them attractive materials for sensing applications. Correlating the crystalline structure of the films to their electronic properties is the key to understanding their multiferroic behaviour. In this project, the REU student will perform detailed XRay Photoelectron Spectroscopy (XPS) investigations of BiFeO₃ films of 10 - 200 nm thickness. Information about the Bi and Fe oxidation states within the film, at the film surface, and the film-support interface will be obtained from angle-resolved measurements. To facilitate assignment of oxidation states, reference measurements will be conducted on standard bulk samples of Fe (II) and Fe (III) oxides. This project involves a collaboration with the Ramesh group, who will prepare films and perform structural measurements. In addition to the XPS measurements, the REU student will have opportunities to learn about film growth and structure.

Pattern Formation in Granular Media

Unlike fluids, which tend to mix when stirred, mixtures of granular materials segregate into bands, when one attempts to mix them in a horizontal tumbler. In this project, we investigate the mechanism that leads to this banding. The student will use high resolution imaging and image analysis to study the evolution and oscillations of band patterns generated by mixtures of three or more granular materials. In addition, the student will use high speed imaging and particle tracking software to analyze the granular flow in detail for comparison to models. Please contact Dr. Losert or visit www.ireap.umd.edu/granular/ for more information about ongoing projects.

Molecularly Imprinted Polymers for Isomeric Sugar Biorecognition

Molecular imprinting is an emerging technology which allows the synthesis of materials containing highly specific receptors sites having an affinity for a specific target compound. Biorecognition is achieved as a result of the presence of appropriately arranged functional groups in a mechanically stable matrix. The goal of this project is to produce molecular imprinted polymers (MIPs), which only selectively bind specific sugars. The preliminary results indicate that a hydrogel can be produced, which can specifically and selectively bind glucose even while in its water-swollen state. The clinical relevance of this research relates to the development of a pharmaceutical based on such MIPs, which will aid in the treatment of Type II diabetes, and in the treatment of obesity. Applying the proposed MIP technology to a pharmaceutical or a food additive could contribute to the dietary freedom of those who suffer from type II diabetes. By ingesting these materials, the glucose would be absorbed by the hydrogels in the stomach and small intestine prior to digestion, thereby reducing the amount of sugar actually introduced into the blood stream. The sugar laden hydrogel would then pass, undigested, through the remainder of the gastrointestinal tract to be expelled by the bowel. simple analogy can be made to the the application of these materials in the treatment of obesity as well. By binding the glucose prior to absorption by the body, the net caloric intake with respect to the number of calories ingested would be reduced. Another clinically relevant application of the MIP technology is the development of an implantable glucose sensor for diabetic patients, which would provide an alternative to the present discrete methods of glucose determination that are based on intermittent blood sampling. Continuous glucose sensing would be particularly important in the detection and management of hypoglycemia, by providing a method for early detection of the condition and a basis for insulin administration at more appropriate dosages. Such MIPs could also be used for bio-separations in conjunction with chromatographic techniques to separate amino acids, drugs, sugars and other compounds.

Ultrafast Polarization Switching Dynamics of Ferroelectric Memory

Ferroelctric material can potentially be a very good material for random access memory. In order to write and read the information at high data rate, one has to investigate the speed of polarization switching of this class of material. We investigate the switching dynamic at the picosecond time scale by generating ultrafast risetime electrical pulses using photoconductive switches. In this research REU students will learn the fundamental of design and testing of ultrafast photoconductive switches and basic measurements associated with such devices.

Molecular Rulers – The Next Generation of Tools for the Nanoworld

What is the width of a liquid interface? What sort of environment does an anaesthetic see inside of a cell membrane? What properties account for the stability of emulsions? Answers to these questions require being able to position a probe and well-defined positions relative to a nominal, soft-surface boundary. We accomplish this task by building and characterizing new families of surfactants, dubbed molecular rulers. Molecular rulers consist of a polar (or charged) headgroup connected to a hydrophobic chromophore probe by a variable length alkyl spacer. We have exploited these molecular rulers to measure the dipolar widths of different liquid/liquid interfaces.

This summer’s project is to build the next generation of molecular rulers – this time using the biologically active chromophore indole as the hydrophobic probe. Participants in this project will learn simple synthetic methods as well as state of the art characterization techniques, including techniques used to quantify surface activity and photophysical behavior.

Directed evolution of semiconductor surfaces through spatial patterning and growth or sublimation.

The continued drive toward devices of ever-smaller dimensions and simultaneously higher densities is expected to exceed the capabilities of existing photolithographic and direct-write technologies within the next several years. Continued progress will require a new paradigm. One of the most promising is that of directed self-assembly, i. e. inducing a spontaneous ordering of atoms or molecules into useful structures using some sort of spatially modulated field or template. The experiments use both epitaxial growth of ultra thin semiconductor films on patterned substrates and sublimation from patterned substrates to control the structures which develop. This project will include both involvement in atomic force microscopy measurements of the structures, and analysis of the results.