Date of Award

May 2019

Degree Type


Degree Name

Master of Science



First Advisor

Marcia R Silva

Committee Members

Nathan Salowitz, Lucas Beversdorf


Biofilm sensor, Biofilms in Piping systems, Detection of Biofilm, non-invasive sensor for detection of biofilm, Novel sensor for detection of biofilm, Ultrasonic sensor for detection of biofilm


Biofilms are formed when a group of cells of microorganisms stick to each other and often on a surface. The development of biofilm has been a major issue in many fields (medical field, food, chemical, and water industry are a few such fields). In the medical field alone, biofilm infections have reportedly cost over five billion USD in additional healthcare expenses. The food industry usually halts the operation of its plant eight hours, every day to ensure that their equipment and transportation channels are clean and free from any biofilm presence. Similarly, the water and chemical industry need to ensure that their transportation channels are free from biofilm build-up to ensure that the flow rate of liquid flowing through the channels is neither affected nor contain bacterial traces. There is an immediate need for new technologies, that are both real-time and non-invasive that can be used to quantify biofilm formation in closed systems, which can reduce the loss incurred by the healthcare, food, chemical and water industry.

This study investigates the use of a novel non-invasive and real-time technique that consists of two ultrasound sensors which can be mounted on a piping system. In this study, voltage and phase shifts were detected in materials with thickness greater than 40 µm, indicating that the sensor arrangement can be used to detect biofilm of thickness greater than 40 µm in a closed piping system. The results of objects present in the closed system cannot be obtained using conventional techniques such as the Raman microscopy, confocal laser scanning microscopy (CLSM) or other microscopy methods. This technique also allows in-situ detection (i.e. it avoids the need for inserting or extracting a coupon from the medium for measurement and eliminates the need to obstruct the operation of the system or the flow of measurement media through the system).