[1] A. Kamholz and P. Yager, Biophysical Journal 80, 4891 (2001).

[2] N. Darnton, O. Bakajin, R. Huang, B. North, J. Tegenfeldt, E. Cox, J. Sturm, and R. Austin, Journal of Physcics: Condensed Matter 13, 4891 (2001).

[3] J. Wu and H. Keh, Colloids and Surfaces A 212, 27 (2003).

[4] S. Zeng, S. Chen, J. Mikkelsen, and J. Santiago, Sensors and Actuators B 79, 107 (2001).

[5] S. Maiti, U. Haupts, and W. Webb, Proc. Acad. Sci. USA pp. 11753-11757 (1997).

[6] S. Shiokawa, Y. Matsui, and T. Ueda, Ultrasonic Symposium pp. 643-646 (1989).

[7] J. Campbell and W. Jones, IEEE Transactions on Sensors and Ultrasonics 17, 71 (1970).

[8] W. Nyborg, Physical Acoustics 2B, 265 (1965).

[9] T. Uchida, T. Suzuki, and S. Shiokawa, IEEE Ultrasonic Symposium pp. 1081-1084 (1995).

[10] D. Magde, E. Elson, and W. Webb, Physical Review Letters 29, 705 (1972).