Multiplexed Organic Chemistry

The practice of sharing and extracting multiple signals over a singular medium, commonly referred to as multiplexing, is ubiquitous in telecommunications, computer networking, and biology. However, due to low reaction efficiency, lack of visual cues, and need for purification/structural identification, multiplexing (or obtaining diverse output from limited input) is uncommon in organic chemistry. Difficulty in multiplexing organic chemistry is further compounded by the fact that reactions that create a diversity of products or outcomes are normally viewed negatively and are avoided in favor of clean, high yielding, but inherently limited processes.

Taking note of highly multiplexed platforms developed in other fields, this program will be geared towards the creation of their chemistry equivalents, with goals ranging from the discovery of new reactions to the production of functional macromolecules, molecular machines, smart materials, and drug candidates. These platforms will be developed where simple inputs are submitted to a single or limited number of operation(s) that generates diverse outputs, effectively harnessing the inherent messiness of organic chemistry coupled to simple visual readouts.

Multi-Material Additive Manufacturing

The global economy necessitates short production cycles for consumer and industrial goods with a high level of control over design and material properties. This maxim has led to the widespread adoption of additive manufacturing, or 3D printing, to rapidly prototype a large variety of plastic materials without need for costly, machined molds. Despite many recent advances in this field, printing parts with variable material properties (namely glassy or rubbery) from a singular resin remains elusive. State-of-the-art approaches rely on one of the following: 1) mixtures of different multifunctional monomers (e.g. acrylate and epoxide) that can undergo polymerization orthogonally to yield different material properties (glassy vs. rubbery), or 2) purposefully converting a singular multifunctional monomer to varying extents, thus, manifesting different material properties (as above). In either case, a large concentration of unreacted material remains in the printed part, leading to inconsistent mechanical performance and a short shelf life.

This program will draw upon existing 3D printing techniques that use light to create printed parts. Like previous approaches, this platform will use two wavelengths of light to spatially create different material properties. Unlike previous approaches, this will occur by varying the manner in which a singular functional group is converted to a polymer. These two modes of reactivity, which are tied to catalysts released at different wavelengths, will result in no unreacted material remaining in the printed part. Moreover, as a single, commercially available resin will be utilized, little to no phase separation will occur. Long term goals of this project will be directed towards the formation of bioinspired materials that spatially combine rubbery and glassy regions to make incredibly robust materials.