Session: 11-45-01: Technique development for thermophysical characterization

Paper Number: 111701

111701 - Developing a Floating Calorimeter for in Situ Study of Microbial Activities Near Coral Reefs 

Calorimetry is a powerful tool for measuring thermodynamic properties and has been widely used in various research and industrial applications. In the pharmaceutical industry, calorimeters are used to measure the thermodynamic properties of chemical reactions, especially binding affinities between proteins and drugs. Physical properties such as specific heat can also be determined through experiments conducted by calorimetry, which is an important parameter in the manufacturing and transportation industry. 

Calorimeter has the potential to revolutionize the way researchers study microbial activities near coral reefs. Coral reefs are vital ecosystems that provide shelter and resources to a vast array of marine life, and they are also important contributors to the global economy through tourism and fisheries. However, coral reefs are facing unprecedented threats from climate change, pollution, and overfishing, among other factors. Monitoring the health of coral reefs is therefore crucial for their conservation and management.  

One way to assess the health of coral reefs is by studying the marine microbes living near the reefs. The goal of studying marine microbes living near coral reefs is to analyze their activities, particularly their consumption of dissolved organic compounds (DOC) generated by the reefs. By measuring the heat released by these microbes, researchers can gather valuable information about the health and productivity of the coral reef ecosystem. 

The Marine Microbe Laboratory at San Diego State University (SDSU) is currently studying the behavior of marine microbes by measuring the heat released through calorimetry. However, current commercial calorimeters have limitations and restrictions that prevent in-situ experiments from being performed. To address this challenge, a novel floating calorimeter (FC) is being proposed by researchers at Northeastern University and the Microfluidic Laboratory at the Mechanical and Industry Department. The FC design is based on a photonics-based nanohole array sensor (NHA) that combines surface plasmon resonance (SPR) and extraordinary optical transmission theory (EOT). This design allows for accurate and immediate data collection at the beginning of a reaction with precise measurements (i.e., 0.001°C) and a small body size that can conduct in-situ studies, thereby extending the possibility and variability of experimental designs. 

The FC design includes a unique chamber that allows microbes to free flow under seawater environments in a round shape. The FC calibrates in three phases: air environment, immersed in water after sealing, and simulating an aquatic environment to realize in-situ microbe experiments. The FC is effective in conducting in-situ experiments, which will provide researchers with richer and more varied data sets. The updated 96-well plate structure version of the FC meets the standards of the pharmaceutical industry, providing an additional tool for drug discovery. 

The proposed FC has the potential to revolutionize the study of marine microbes by providing a new method for in-situ experiments. The ability to conduct experiments in their natural environment will provide researchers with more accurate and comprehensive data that can inform efforts to protect coral reefs and other ecosystems. The FC may also be applied to other fields, such as the manufacturing and transportation industries, where specific heat measurements are important.  

This paper describes the design, prototype construction, calibration, and testing experiments protocol of the floating calorimetry, providing proof of concept for the possibility of photonic-based calorimeter physics to be extended to an ocean environment involving marine microbes. The initial results and next step plan will also be discussed. Overall, this research demonstrates the potential of new technologies to advance scientific understanding and contribute to positive change.  

Presenting Author: Yuwei Zhang Northeastern University

Presenting Author Biography: Yuwei Zhang is currently a Ph.D. candidate at the College of Engineering, Northeastern University in Boston. She completed her MS in Mechanical Engineering, in 2019 at Northeastern University. She obtained her BS, in Energy and Power Engineering at Huazhong University of Sci & Tech, Wuhan, China. Her current research focuses on measuring microscale energy related, applying calorimetry studies in microbiological and pharmaceutical areas, simulating heat transfer models, and computational fluid dynamics. She has been a member of the American Society of Mechanical Engineers (ASME) since 2022. She is good at representing research work and communication. She received a research poster award and academic technology scholarship in 2021.

Authors:

Yuwei Zhang Northeastern University
Gregory Kowalski Northeastern University