🏆 Best Poster – Third Place
The team worked with Philips Ultrasound to redesign and test the conductive backing wafer component of the acoustic stack in their ultrasound transducers with regards to mechanical, electrical, acoustic, and thermal properties to process and characterize acoustic layers which are rigid, machinable, diceable, both thermally and electrically conductive, and attenuative at frequencies of interest.
Sponsored by: Philips Ultrasound
Team Members
Nikhila Kumar Jordan O’Donnell Ron Rogers Emily Snow Thomas Worcester Harsh Zaver
Instructor: Dr. Robert Allen Kimel
Project Poster
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Project Video
Project Summary
Overview
To increase the efficiency of Philips Ultrasound Transducers, the team was tasked with formulating and testing new materials for the conductive backing wafer within the acoustic stack of the current ultrasound transducer. Currently, the composition of the conductive backing wafer material contains conductive fillers that are causing short circuits during the dicing process. To reduce occurrences of the shorting, new formulations were tested to replace the conductive backing wafer.
Objectives
– Explore novel backing material compositions
– Fabricate new material wafers
– Test the four formulations to characterize rigidity, machinability, diceability, both thermal and electrical conductivity, and attenuation at frequencies of interest
Approach
The data collection process included mechanical, electrical, acoustic, and thermal tests. The tests included:
– 3-point bending tests to characterize the elasticity
– Electrical resistivity measurements to determine the electrical resistance
– Bulk acoustic tests to measure velocity, attenuation, and acoustic impedance
– Scanning acoustic microscopy to characterize uniformity
– Differential scanning calorimetry to observe cure and transition temperatures.
Outcomes
After data collection, the group noted and characterized the similarities and differences between the tested formulations and the provided reference data for the current material selection of the conductive backing wafer. Formula 2 had the highest acoustic impedance values, while Formula 8 had the lowest acoustic impedance. Additionally, Formula 2 had the lowest electrical resistance values, while Formula 8 had the highest electrical resistance. Given these formulations portrayed the extremes of the data, these formulations were chosen to proceed with further testing at Philips to reintroduce back into the acoustic stacks in their ultrasound transducers.