David Jangraw


2008 to 2014: EEG and Brain-Computer Interfaces
As a PhD candidate in Columbia University’s Biomedical Engineering Department, I was a member of Paul Sajda’s Laboratory for Intelligent Imaging and Neural Computing (LIINC). During that time, I worked on a number of projects including a 3D experimental design software package, a closed-loop brain-computer interface (BCI) + computer vision system for image classification, and a free-viewing paradigm to study evidence accumulation.

2007 to 2008: Visual Attention in the Rhesus Monkey
Working with Professor Jacqueline Gottlieb, I spent a year at Columbia Medical Center experiencing a full immersion in experimental neuroscience.  Professor Gottlieb’s lab uses electrophysiology to study single cells in the Rhesus monkey. Our project looked at visual attention and studied the effects of reward expectation on the brain’s visuospatial map of attentional significance.

Spring 2007: Memory Networks and STDP
During the spring semester I worked one-on-one with Princeton’s incomparable Professor John Hopfield to refine a computational model of associative memory.  Using mathematics and a truckload of MATLAB, I explored the effects of this new addition to the model, from a single “integrate-and-fire” neuron to multiple, dynamic synapses.

Summer 2006: Capacitive Distance Probe
At GE I worked on a capacitive distance-measuring probe for use in the new GE-nx aircraft engine.  As part of a team headed by James Simpson, I tested the current design, suggested improvements to the testing apparatus, and analyzed experimental data and ANSYS modeling results using MATLAB.

Summer 2005: New Electroplating Techniques
This summer was spent investigating improvements in the process of electroplating.   I did literature research on techniques and materials, investigated the current electroplating setup firsthand in a cleanroom setting, and looked into the costs and benefits of changing and updating our setup in various ways.   I then discussed possible options with Professor Gmachl, and began to implement the improved setup.

Summer 2004: Quantum Cascade Lasers
I began by learning the basics of tiny quantum cascade lasers (or QCLs) and researching the pros and plausibility of using Group IV semiconductors (specifically Silicon and Silicon-Germanium, or SiGe) as materials for making them.  We had a simple sample produced, which I helped mount and tested for light emission.  I designed a new sample holder to accommodate the bi-directional light emission made possible by new lasers like this one.  In an unrelated project, I used a laser design simulation to design a new ‘excited-state’ QCL and optimize its theoretical performance.