FUTURE WORK:• After developing a prototype for the

sensor, we will work to integrate into a Thermo Fisher SUB Fermenter system by physically attaching the sensor and building a program to integrate the sensor readings to a Thermo Fisher controller for testing.

• Testing will be done in a 30L fermenter by first using a Pluronic to create foam for sensing, and then testing the sensor's foam detection in a small-scale batch fermentation

• The prototype will also be reevaluated for scale up and integration into larger Thermo Fisher SUB Fermenter sizes

CURRENT WORK:• Developing design ideas• We will be working on selecting a single

design and pursuing the development of a prototype.

• In the next weeks we plan to 3D print the device and incorporate our sensors so that we may begin initial testing on a Thermo Fisher bioreactor.

BACKGROUND:• Single Use Bioreactors (SUBs) are used

for microbial cell culture for many industries, such as biopharmaceuticals, cell cultures of pilot-studies, food, and cosmetics1.

• One problem is accurate level sensing of different levels of culture and foam.

• Our goal is to develop an adjustable optical foam level sensor for the Thermo Fisher Dyna-Drive SUB that is scalable for batch volumes of 6 L to 5KL.

Proposed Foam Sensor for Single Use Bioreactors (SUB)Alyssa Cisneros1, Harley Cragun1, Crystal Rain Fowler1, Mikelle Kearnes1, Annika Saunders1, Dr. Jixun Zhan1, Jason Brown2

Utah State University1, Thermo Fisher Scientific2

DESIGN 1: Ultrasonic Level SensorUse: The ultrasonic level sensor is a contactless sensor that emits a high frequency acoustic pulseto the surface of the foam. This pulse is reflected back to the transducer to measure the time offlight and is converted to distance.Implementation on Bioreactor: This sensor would require a housing unit to be developed that would attach it to the top of the bioreactor and face it downward. A preliminary diagram of the implementation can be seen in Figure 1.Safety to culture: Since the sensor would sit within the top port of the bag, there is little risk to culture unless foam control methods fail, and overflow occurs.Cost: Prices range from $550-$750 depending on the desired range of sensing.Manufacturability: Because this sensor would simply need a housing unit to fit the requirements of the project, the manufacturing process is simplified.

References(1) W. Meusel, C. Löffelholz, U. Husemann, T. Dreher, G. Greller, J. Kauling, D. Eibl, S. Kleebank, I. Bauer, R. Glöckler, P. Huber, W. Kuhlmann, G. T. John, S. Werner, S. C. Kaiser, R. Pörtner & M. Kraume. (2016). Recommendations for process

engineering characterisation of single-use bioreactors and mixing systems by using experimental methods. Dechema.(2) Vadar-Sukan, F. (1998). Foaming: Consequencs, prevention, and destruction. Biotechnology Advances. 16(5-6),913-948. https://doi.org/10.1016/S0734-9750(98)00010-X.

DESIGN 2: Photoelectric Optical SensorUse: The photoelectric sensors fall into the contactless detectors in the Foam sensing category. Traditionally, photodetection of foam have been used before2. A commercial example of a diffuse photoelectric optical sensor used for detecting foam is the Foam Fighter by ReseaTech. However, there are limited designs and research that use a photoelectric optical sensor as a foam sensor. Therefore, the use of a photoelectric optical sensor would be considered a novelty approach to detecting foam.Implementation on Bioreactor: A housing unit would be necessary to attach on the side of the that the window would be on. A preliminary diagram of the housing unit and sensor can be seen in Figure 2.Safety to culture: As a contactless solution to detecting foam, there would be no danger or need to autoclave the sensor.Cost: For commercially available sensors, the photoelectric sensors are in a price range from $100 to $300 for 5m (from Grainger Industrial Supply). These price ranges can increase, based on the sensor range. Manufacturability: A unique housing unit for each bioreactor from the 6L to the 5KL would be needed to be manufactured in order to use this type of sensor to detect foam. However, a 3D printing the housing unit would significantly lower the cost, making the manufacturing process simplified.

Proposed Design Process

3D Computer Aided Design (CAD) Model of Design

3D Housing Prototype with Sensors

Sensor Programing and Surfactant Testing with a 30L bioreactor

1 2 3 4Culture Testing with 30L bioreactor

Foam

Impeller

Housing Unit

Photoelectric Optical Sensor

BPC

Foam

Impeller

Housing Unit

Ultrasonic Sensor

BPC

Figure 1. Ultrasonic level sensor implementation with housing unit on bioreactor..

Figure 2. Photoelectric optical sensor implementation with housing unit on bioreactor..

AcknowledgementsWe would like to thank our industry mentor, Jason Brown, and our university mentor, Dr. Jixun Zhan, for their support and guidance in completing this project. We would also like to thank our industry

sponsor, ThermoFisher Scientific for their financial and professional support.