The National Academy of Engineering and the UC Davis College of Engineering hosted a very interesting Symposium on Manufacturing in April. The public part of the meeting featured eight outstanding speakers and presenters, but I'll report on only one today. It was "Miniature chemical sensors and smart algorithms for non-invasive biological monitoring," presented by Dr. Cristina Davis, who is Professor of Mechanical and Aerospace Engineering at UC Davis.
Great progress has been made with chemical sensors over the past decade and Professor Davis's leadership is making UC Davis one of the top U.S. campuses in the field with her Bioinstrumentation and BioMEMS Laboratory (MEMS stands for microelectromechanical devices). Her research group composed of five senior researchers, nine graduate students, and seven undergraduate students "focuses on cutting edge research on the design and implementation of analytical sensors — especially chemical sensors."
According to the Lab's website, "There exists an urgent need for sensors that can rapidly, accurately, and specifically detect extremely small concentrations of chemical and biological materials. uch technologies can make an impact on everything from public health to national defense.
"Along with researchers in industry, our group is developing new sensor systems suitable for rapid diagnosis of various pulmonary diseases. Similarly, we are also applying variations on this technology for the early detection of chemical and biological agents. By drawing parallels in chemical/metabolite detection for clinical and defense applications, we can now develop 'dual-use' sensors that are less expensive to bring through the development pipeline and can be applied to a wide spectrum of problems.
"This core thrust in our research requires a multidisciplinary effort between biology, chemistry,mathematics, mechanical, and electrical engineering."
Davis described how the Lab's work can be applied in three fields of life science. Metabolism is the set of life-sustaining chemical transformations within the cells of living organisms (including both plants and animals). These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. In the metabolic process, humans take in food, water and oxygen. Many diseases can be diagnosed by analytic sensors that can identify the composition of extremely minute quantities of chemical compounds (biomarkers) that we exhale.
In the field of breath analysis, the Lab's research group "has several clinical trials to determine disease-specific breath biomarkers underway, and also parallel device development to exploit these markers. The totally non-invasive nature of breath diagnostics makes it very appealing for routine and rapid testing in the clinical point-of-care setting. We can not only diagnose health status, we can also chart patient response to therapy. Our goal is to construct microsystems for health analysis, and to identify specific breath biomarkers of lung and systemic diseases." One disease under study is asthma, which affects more than five million people in California. Others include cancer and diabetes.
Another field that Dr. Davis talked about was volatile organic compounds (VOCs) in plants. As most of us learned in school, humans and animals inhale oxygen and exhale carbon dioxide while plants do the opposite. By analyzing the minute quantities of VOCS released from plants along with oxygen, they can be monitored non-invasively in their processes of flowering, ripening, maturing, stress, and disease. "Our research group is developing new portable VOC detection systems that can be used in the field to monitor plant VOCs for precision agriculture." One plant disease that can have a devastating effect on California is called citrus greening disease or Huanglongbing (HLB) disease. Researchers in Dr. Davis's Lab have developed a potable chemical sensing system that "sniffs" VOCs given off by the leaves of orange trees. In tests of the system they have found dramatic differences in the VOCs sensed from healthy trees and diseased trees not yet identified by other means.
A third field Dr. Davis spoke about is in the study of life processes of marine mammals such as dolphins and whales. A common method for analyzing metabolic and other health processes in most animals is through blood testing, but that is almost impossible with sea mammals. However, whales have blowholes in the top of their heads from which samples can be taken. While it is quite easy to sample the breath of captive sea mammals, even wild ones have been sampled by instruments on lines below helicopters and on poles from ships that manage to get close to them.
Finally, another field in which the Lab is developing sensors is national security and biodefense in applications like "detection of chemical warfare agents, toxic industrial chemicals, and select agent pathogens."
The author is retired from the U.S. Air Force, lives in Dixon and serves on the Solano County Board of Education.