My latest work focuses on building integrated molecular circuits using DNA self-assembly as a bottom-up fabrication strategy and resonance energy transfer (RET) logic as a means of computation. Although unlikely to directly replace silicon based electronics, these integrated circuits offer more than a 1000 fold increase in device density over the current CMOS node at a fraction of the cost. More importantly though, based on their sheer size and chemical composition, these molecular-scale circuits have the potential to offer computation in entirely untapped domains, like the aqueous environments that silicon computers fear.
To fabricate these circuits, we use fully addressable, hierarchically assembled DNA lattices, which serve as nanoscale breadboards for positioning individual molecules with sub-nanometer resolution. Logic gates are composed of fluorescent molecules, or fluorophores, arranged into predefined spatial patterns on the DNA substrate. These networks perform Boolean operations using RET to move and manipulate information. Inputs to these circuits are supplied as photons that excite designed wavelength-multiplexed input fluorophores. This excitation generates excitons that flow through the network until reaching designed output fluorophores. The results of the computation are ultimately relayed back to the user as a fluorescence signal with information encoded in both the time and wavelength domains. The image above captures the results from one such experiment in which these computational devices are diffusing through a cuvette, emitting a bright green fluorescent signal.
For my doctoral thesis, I have developed a new set of cascadable RET logic gates for building complex, scalable RET logic. More information regarding this work will be available by the spring of 2017.
LaBoda, C., Dwyer, C. L., Lebeck, A. R. (2017). Exploiting Dark Fluorophore States to Implement Resonance Energy Transfer Pre-Charge Logic. IEEE Micro. In Press.
LaBoda, C., Lebeck, A. R., Dwyer, C. L. (2017). An Optically Modulated Self-Assembled Resonance Energy Transfer Pass Gate. Nano Letters. 17:3775-3781.
LaBoda, C. (2017). Devices and Circuit Design Strategies for Building Scalable Integrated Molecular Circuits. PhD Dissertation. Duke University.
LaBoda, C., Duschl, H., and Dwyer, C. L. (2014). DNA-Enabled Integrated Molecular Systems for Computation and Sensing. Accounts of Chemical Research. 47:1816-1824. (pdf) (shared cover article)