Our senses form the basis by which we understand, observe, and interact with nature. Thus, our human experience is arguably rooted in sensing (i.e., the acquisition, conversion, analysis, and interpretation of signals.

As engineers, sensing also provides the basis for analyzing (i.e., understanding), monitoring (i.e., observing), controlling (i.e., interacting with), and designing novel and complex processes and systems.  Similar to our human experience, the quality of reasoning, decision making, and control outcomes in an engineering context is dependent on rapid, accurate, and resilient sensing. 

Among sensing applications, the detection, identification, and quantification of biomolecules and biologics, commonly referred to as ‘chemical sensing’ and ‘biosensing,’ is central to analyzing, monitoring, controlling, and designing complex processes and systems with applications across several industries, including medical diagnostics, biomanufacturing, environmental protection, and defense. 

For example, the concept of a reaction is foundational to the analysis (e.g., modeling) of many complex processes and systems, such as biological processes, that involve generation or consumption of resources (e.g., molecules, materials, information, energy).

For example, consider the generation of products (P & Q) from available industrial waste or sustainable resources (A & B), which can be modeled as a chemical reaction:

A + B + … <---> P + Q + …     (Equation 1)

where A, B, P, and Q represent arbitrary reactants and products.  While Equation 1 is foundational to modeling of traditional chemical processes, it is also central to modeling of ‘bioprocesses’ (i.e., chemical processes driven by microbial technology).  And that's where the story gets interesting.

Bioprocesses are central to establishing smart and resilient food, energy, water, healthcare, and defense systems, and thus, play a significant role in driving economic growth (e.g., via disruptive technology and sustainability), environmental protection, and national security.  Ideally, we would like to continuously monitor and control complex bioprocesses in real time, such as those associated with production of drugs, spread of pathogens, or remediation of industrial waste by detecting, identifying, and quantifying (i.e., sensing) the species involved in the reaction in real time (often these species are critical inputs or products themselves).  However, it remains a challenge to create sensors capable of continuously sensing chemicals and especially ‘biologics,’ which include biomacromolecules and cells, which often require the use of a ‘biorecognition element’ for detection, due to present barriers in biosensing technology and methodology.   Chemical sensors employ a selective material (often a polymer) for detecting the target analyte, while biosensors employ a selective ‘biorecognition element’ (often an enzyme or antibody) for detecting the target analyte.

Grand Challenges in Biosensing: Specifically, measurement reliability (e.g., accuracy and resilience) and speed (i.e., mitigation of time delay) are critical technical challenges that must be overcome to create high-performance biosensors capable of continuously monitoring and controlling bioprocesses and associated biomanufacturing processes (e.g., bioreactors).   In several applications, such as those that require affinity-based biosensors, biosensor saturation is also a significant technical challenge that limits continuous monitoring applications.  And, while various approaches have been established for biosensor regeneration, such methods often insult the biosensor with chemicals that may affect the biosensor performance (e.g., stability of the biorecognition element).

Our lab is focused on addressing these challenges through interdisciplinary research in several engineering disciplines (primarily, chemical, mechanical, and electrical), computer science, and applied mathematics.

So Who Cares?: Rapid and reliable detection, identification, and quantification of biologics, which include biomacromolecules, viruses, and cells (e.g., microbes), is central to critical components of the United States primary, secondary, and tertiary industries (and thus, the US economy), national security, fundamental research, and emerging technologies that benefit humanity.

While several ‘methods-based assays’ exist for quantifying the concentration of molecules in a sample (e.g., ELISA, PCR), device-based sensing (detection, identification, quantification) of fluid and material composition using chemical sensors and biosensors is central to quality control in various critical industries, including medical diagnostics and biomanufacturing, and fundamental research in various fields, including materials science and tissue engineering. For example, a miniaturized device can be integrated directly with a process and generate a continuous signal that can be utilized for monitoring and control applications.  While various device-based chemical sensing and biosensing technologies have been examined to date for sensing of material composition, the complexity of bioprocesses that generate the data and inform the decision making objectives, such as those found in modern medical diagnostics, biomanufacturing, and biosurveillance applications, requires continued innovations in sensing (e.g., sensor design, manufacturing, and analytics).  

We are inspired by the sentiment "If you can't sense it, you can't control it." Our group is focused on making fundamental advancements in the field biosensing as well as the fields of autonomous chemistry and biomanufacturing via sensing innovations. 

Many of our current research projects are inspired by fundamental research in analytical chemistry and signal processing as well as the Materials Genome Initiative and COVID-19 pandemic, which motivate the need for advances in smart sensing and smart biomanufacturing. Specifically, our lab is focused on establishing novel methods for autonomous chemistry and smart sensing via theory-guided machine learning.

Research on sensors and sensing, and applications thereof in the biosensing and biomanufacturing domain, is interdisciplinary and applies theory, principles, and methodology from various engineering disciplines as well as computer science, neuroscience, biology, chemistry, and physics.  Students from all backgrounds are welcome to venture deeper into the fascinating world of autonomous chemistry, smart sensing, and Biomanufacturing 4.0.