AbstractDemands to handle individual particles or particle agglomerates have been emerging in the fields of biology and chemistry, and particle trapping and manipulation with mechanical waves generated from ultrasound sources, known as “acoustic tweezing”, has gained great interest by researchers and been proved useful for its unique advantages. With an analogy to optical tweezing, research has demonstrated the possibility to use modulated acoustic fields generated by ultrasound arrays for trapping individual particles and groups of particles at length scales from hundreds of µm to a few mm.
This thesis explores and demonstrates particle trapping and manipulation with electronically-controlled miniaturized ultrasound arrays (element pitch around 500 µm or less), focusing on the development of dexterous electronic systems. Generally, in acoustic manipulation applications, low voltage outputs with continuous mode operation are required to create stable acoustic energy potential “landscapes” for trapping without damaging particles or cells.
The research work of this thesis is oriented towards integration of control electronics with miniaturized ultrasound arrays. Test fixtures have been carefully designed and fabricated for the characterization of transducer arrays developed by collaborating researchers and array-controlled particle manipulation experiments have been demonstrated with customized fluorescence microscopy equipment.
Most importantly, this thesis has established two versions of prototype Field programmable gate array (FPGA) based electronics to drive ultrasound arrays. One is a computer-controlled 16-channel system, with adjustable output frequencies, phases and amplitudes. Another is a 40-channel switching electronics for manual controlled output switching or time-shared output multiplexing. The electronic systems that have been developed are highly scalable and easily adapted for different acoustic tweezing applications.
In conclusion, this thesis has proposed prototype electronic toolkits as research platforms to explore diverse possibilities for acoustic tweezing with miniaturized ultrasound arrays.
|Date of Award||2015|
|Supervisor||Sandy Cochran (Supervisor) & Christine Demore (Supervisor)|
- Acoustic Tweezing
- Ultrasonic manipulation