Investigating Feedback Systems in Nature and Engineering

Eduardo Sontag

University Distinguished Professor Eduardo Sontag, electrical and computer engineering (ECE), jointly appointed in bioengineering, and affiliate faculty in chemical engineering and mathematics, was awarded a $750K grant from the Air Force Office of Scientific Research, titled “Network Motifs and Responses of Nonlinear Systems.”

The award will support his research into the mathematical foundations of biomolecular feedback control and signal processing. The project aims to explain how responses to external stimuli provide information regarding the internal structure of synthetic and natural cellular networks, elucidating the behavior of natural systems as well as helping to improve feedback control in engineered systems.

The feedback mechanisms underlying a wide variety of unrelated applications can be studied through the common lens of the field of mathematics called control theory.  Sontag has devoted much of his professional life to this area of work, and specifically to the development of the theoretical foundations of nonlinear control systems analysis and design.

In engineering, feedback control plays a central role in aerospace, manufacturing, robotics, chemical processes, electrical power systems, consumer products, medical devices, self-driving cars, mobile communications, and many other areas.  In nature, physiological feedback loops are key to homeostatic mechanisms that finely tune temperature, blood pressure, calcium, sugar levels, body fluids, and balance, in humans and animals. They also manage the delicate interplay between infections, tumors, and the immune system, and help marshal defenses against invading pathogens. Inside individual cells, feedback systems regulate the dynamic behavior of complex molecular reaction networks composed of interacting genes, mRNA’s, proteins, small molecules, and metabolites, orchestrating exquisite information processing, regulatory, and dynamic behaviors that constitute life itself.  In synthetic biology, bioengineered cells are endowed with circuits that control gene expression for therapeutic applications. At the level of entire populations, the stability of ecological systems depends on predator/prey as well as competitive and cooperative interactions. In economics, money supply and interest rates are employed as feedback controls. In pandemics, interactions of individuals are tuned through levels of “social distancing” and other “non-pharmaceutical interventions” designed to balance intensive care unit usage.

“This award nicely complements the recently announced $7.5 million grant from the Department of Defense Multidisciplinary University Research Initiative competition sponsored by the Office of Naval Research to ECE professors Mario Sznaier, Octavia Camps, Milad Siami, and myself, and it helps establish Northeastern as a top leader in the field,” said Sontag.

Related Faculty: Eduardo Sontag

Related Departments:Electrical & Computer Engineering