Hamilton Institute Seminar

Wednesday, February 2, 2022 - 13:00 to 14:00

Passcode: 279596

Speaker: Professor Rebecca Schulman, Johns Hopkins University

Title: "Self-assembly of active circuits"

Abstract: In this talk, I’ll try to share some conceptually motivated investigations of how molecules can self-organize.

The wiring of brains illustrates how parallel self-assembly processes can direct the formation of connections of wires from one place to another to form massive, complex circuits.  Inspired by the possibilities of this approach, I will describe work focused on technologies for constructing circuits and circuit connections using biomolecular self-assembly.  Using a process called a point-to-point assembly, we can direct the formation of DNA connectors that bridge two specific molecular endpoints.  Connections can form between endpoints of varying distances that range from 1-20 microns. Multivalent connectors and the ability to form bridges specifically between different pairs of molecules to allow for the creation of more complex circuit topologies.  No fields, flows or other external cues are required for the assembly process, which occurs under ambient or physiological conditions, and because it involves self-assembly, the formation of arbitrarily large numbers of connections can occur in

To use these self-assembled connections, we will not only need to make them but keep them intact in a working device. Living cells control self-assembly and maintain the structure of self-assembled complexes like these networks using chemical reaction networks that actively reform and reinforce structure.  Inspired by these observations, I’ll discuss how we can design “self-healing” dynamics to repair holes and use a generic reaction scheme to maintain materials for growing new parts in a sort of chemical “battery.”  Finally, I will discuss how chemical reaction networks might not only repair devices but also control them.

Bio: Rebecca Schulman is an associate professor in the Departments of Chemical and Biomolecular Engineering (primary appointment), Chemistry and Computer Science, and a member of the Institute for Nanobiotechnology, the Center for Cell Dynamics, and the Laboratory for Computational Sensing and Robotics at The Johns Hopkins University. She develops intelligent and adaptive biomolecular materials and nanostructures by combining ideas from materials science, circuit design, and cell-free synthetic biology. Her work uses techniques from biophysics, biomolecular design, systems design, and machine learning. Recent accomplishments include the development of self-connecting nanowire templates (Nature Nanotechnology, 2017), the creation of materials that use DNA sequences (a genetic code) to direct complex shape changes (Science, 2017), and which can perform signal transduction in situ (Nature Communications, 2017), the design of a toolkit for adding in vitro genetic regulatory networks (Nature Chemistry, 2019) and self-healing structures (Nano Letters, 2019). Dr. Schulman joined JHU after working as a Miller Postdoctoral Fellowship in physics at UC Berkeley. She received undergraduate degrees in mathematics and computer science from MIT and a Ph.D. from the California Institute of Technology. Recent awards include a Hartwell Individual Biomolecular Research Award, a President’s Early Career Award in Science and Engineering (PECASE), a DARPA Young Faculty Award and Directors Fellowship, an NSF Career Award, a Turing Scholar Award, and a DOE Early Career Award.