Graduate Student
Materials Science & Engineering

BS, Massachusetts Institute of Technology, 2001 (materials science & engineering)

Office
Cook Hall 3048
2220 Campus Drive
Evanston, IL 60208-3108
(847) 497-6433 phone
(847) 491-3010 facsimile

Lab
Cook Hall 3020
(847) 497-6415 phone

Email Albert

Albert Hung

Micropatterning of Self-Assembling Systems

Based on the hypothesis that confinement in microenvironments can affect molecular assembly and material behavior, the focus of my research is to micropattern selected self-assembling systems in periodic arrays of single, individually isolated domains of the same orientation for the purpose of characterizing and amplifying their unique properties and possibly create a functional material that could be used in a variety of device applications.

Certain triblock rod-coil molecules developed within the group are known to self-assemble into mushroom-shaped clusters about 10nm in diameter. These structures in turn stack head-to-tail to form lamellar structures that exhibit a net polarity on the local level. However, because of the relatively weak non-covalent intermolecular interactions governing the system, it is thermodynamically more feasible for the material to exist as a polydomain structure of microscopic grains of different orientations, reducing the anisotropic nature of the bulk material. One might imagine that if the aggregates can be divided into a microscopic array of single domains of the same orientation, the resulting material may be macroscopically polar and demonstrate useful properties such as piezoelectricity and second harmonic generation (SHG). Molecular orientation of the micropatterns can be biased by substrate interactions or an applied external field and then probed by optical microscopy, SHG measurements, and near-field scanning optical microscopy (NSOM).

To create the micropatterns, a variety of lithographic techniques are being explored and adapted, particularly soft lithography in which a patterned, elastomeric stamp is used to mold a material from a fluid phase or mixture into periodic features on a substrate. More recently, electron-beam lithography became available in house as a technique for making high resolution, small area patterns for master molds and precision experiments. Other options under consideration include traditional micromachining, anisotropic etching of silicon, and colloidal lithography.