The Bioelectronics and Sensing section performs basic research on biological problems with an emphasis on wound healing. Our group interfaces materials science and solid-state physics with cellular and molecular biology to elucidate fundamental questions of the wound healing process and address roadblocks to aid design of next-generation wound healing materials for the Navy. Cells naturally reside in a complex multi-cue environment, known as the Extra-Cellular Matrix (ECM), comprised of highly organized multi-functional materials. Due to its inherent complexities, the ECM is poorly characterized, and when it is damaged during a wound, the cascade of events to heal the wound is similarly poorly understood. Utilizing state-of-the-art fabrication equipment, our section leverages decades of nanolithography expertise to isolate and fabricate extra-cellular cues that play pivotal roles in the wound healing process and investigate them in a tightly controlled environment.

Current Research

Label-Free Biomolecule Detection

Our section has invented a label-free technique based upon nanoplasmonic imaging which enables the measurement of individual cell secretions with time resolutions below one second and spatial resolutions below 10um. This is accomplished by lithographically patterning gold plasmonic nanostructures into arrays for biomolecule detection via Local Surface Plasmonic Resonance (LSPR). This technology has been used to detect live cell secretions as well as single exosomes.

Haptotaxis Investigations

Cell migration in the crowded in vivo environment is guided in large part by ECM-bound ligands (haptotaxis), which also govern cellular adhesion. Our section has created an experimental platform to investigate haptotaxis that allows for ligand positioning with nanoscale precision as well as highly tunable surface chemistry. This platform offers precise control over nanostructure size, spacing, density, gradients, and disorder to see how these physical parameters effect cell adhesion, viability, morphology, and migration.

Contact Guidance Investigations

Lithographically patterned steps as small as tens of nanometers can cause a wide range of cell types to preferentially orient and migrate along shoulders, a phenotypic behavior known as contact guidance. Contact guidance measurements provide valuable insights into cellular responses such as directed cell migration and are vital for design of smarter wound healing materials. The high-precision nanogrooves shown here shed insight into how cells sense and respond to their substrate topography, enabling researchers ultimately to control and direct cell migration.

Machine Learning for High-Dimensional Data Using Information Geometry

As data spreads into high dimensions, the distance between points becomes large and the corresponding density very low, suggesting the need for an enormous number of points to perform density estimation. But the data may actually lie along low-dimensional manifolds with the local properties of a Euclidean vector space.
Information geometry provides sound procedures for constructing information-theoretic loss functions for manifold learning.