1 Electronic Supplementary Information: Acoustic trap-and-release for rapid assessment of cell motility Minji Kim, a Emma Huff, b Mathieu Bottier, a,c Susan K. Dutcher, c Philip V. Bayly, a and J. Mark Meacham* a a Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130, b Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, c Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110 *Corresponding author: J. Mark Meacham Department of Mechanical Engineering and Materials Science, Washington University in St. Louis One Brookings Drive, St. Louis, MO 63130 Email: meachamjm@wustl.edu Phone: +1 (314) 935-3821 Electronic Supplementary Material (ESI) for Soft Matter. This journal is © The Royal Society of Chemistry 2019