# ISS: Collaborative Research: Acoustic Wave Manipulation of Solder-Joint Defects in Reduced-Gravity Environments

> **NSF 01002526DB NSF RESEARCH & RELATED ACTIVIT** · Virginia Polytechnic Institute and State University (VA) · $178,474

## Abstract

The strength of solder joints can be reduced by pores caused by bubbles trapped during the soldering process. Small bubbles are especially likely to be trapped because their buoyancy is relatively weak, especially in reduced-gravity environments; hence, they do not quickly rise to the surface. This research project will explore acoustic waves as a means of quickly expelling small bubbles from molten solder. Acoustic methods have been used successfully in other situations, e.g. to remove bubbles from cell culture media. This project will transplant those methods to molten solder. Experiments in microgravity will allow acoustically driven bubble motion to be isolated from the effects of buoyancy-driven motion. These data will be used to validate simulations of bubble motion and improve future predictions of the same. The results look to speed up soldering operations and reduce the heat energy needed to keep the solder molten. Additional benefits will come from training next-generation aerospace and mechanical engineers. Experiments in space research provide excellent outreach opportunities targeting high-school students.

This project aims to develop an acoustics-assisted soldering technique and identify the optimal acoustic parameters (e.g., power, frequency, and activation duration) for effective bubble removal. An acoustic transducer will be used to generate waves within molten solder, actively displacing bubbles. This looks to significantly improve the mechanical strength

## Key facts

- **NSF award ID:** 2531908
- **Awardee organization:** Virginia Polytechnic Institute and State University (VA)
- **SAM.gov UEI:** QDE5UHE5XD16
- **PI:** Zhenhua Tian
- **Primary program:** 01002526DB NSF RESEARCH & RELATED ACTIVIT
- **All programs:** THERMALLY DRIVEN PROCESSES, Advanced Materials Processing, MANUFACTURING
- **Estimated total:** $178,474
- **Funds obligated:** $178,474
- **Transaction type:** Standard Grant
- **Period:** 09/01/2025 → 08/31/2028

## Primary source

NSF Award Search: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2531908

## Citation

> US National Science Foundation, Award 2531908, ISS: Collaborative Research: Acoustic Wave Manipulation of Solder-Joint Defects in Reduced-Gravity Environments. Retrieved via AI Analytics 2026-06-06 from https://api.ai-analytics.org/grant/nsf/2531908. Licensed CC0.

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