Fall 2013 Physics Colloquium
November 8; PAS 220, 3pm
Donglei (Emma) Fan
University of Texas at Austin
Characterization and Manipulation of Nanomaterials by Electric Fields
In this talk, I will discuss precision manipulation, assembling, and
actuation of nanoentities by electric tweezers for ultrasensitive
biochemical detection, single-cell drug delivery, and bottom-up assembling
of nano-electromechanical system (NEMS) devices. Electric tweezers are our
recent invention, which utilize combined DC and AC electric fields to
manipulate nanoentities in suspension. Nanowires can be transported in both
the X and Y directions along prescribed trajectories with a precision of at
least 150 nm and rotated with controlled angle, velocity (to at least 26000
rpm) and chirality. Leveraging the unique electric-tweezer manipulation, we
designed, synthesized, assembled, and rotated arrays of plasmonic Raman
nanosensors and investigated their innovative sensing enhancement mechanisms
for single-molecule and location-predictable biochemical detection. We
delivered cytokine functionalized nanowires to a single live cell amidst
many and studied signal transduction mechanisms. We readily determined the
electronic properties of various nanomaterials from their mechanical
rotation in a noncontact and non-destructive manner. We bottom-up assembled
and synchronously actuated arrays of NEMS devices such as rotary nanomotors
and nano-oscillators using nanoparticles as building blocks.