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Note: A simple vibrating orifice monodisperse droplet generator using a hard drive actuator arm
Sebastian Kosch1, Nasser Ashgriz1
1Department of Industrial and Mechanical Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada.
The Review of Scientific Instruments
|May 3, 2015
Summary
Rotary voice coil actuators from hard drives can replace loudspeakers for lab experiments, offering greater amplitude and less noise. This innovation enables controlled droplet generation from liquid jets without complex equipment.
Area of Science:
- Fluid Dynamics
- Mechanical Engineering
- Acoustics
Background:
- Loudspeakers are commonly used as vibration sources in laboratory settings for applications like droplet generation.
- Existing methods often face limitations such as bulkiness, noise production, and insufficient amplitude.
- The need for accessible, high-performance vibration sources in scientific research is ongoing.
Purpose of the Study:
- To evaluate the suitability of rotary voice coil actuators (VCAs) from magnetic hard drives as a superior alternative to loudspeakers for laboratory vibration generation.
- To demonstrate a specific application of VCAs in inducing controlled, monodisperse droplet formation from liquid jets.
- To present a cost-effective and user-friendly droplet generator design utilizing hard drive actuators.
Main Methods:
- Utilized rotary voice coil actuators sourced from discarded magnetic hard drives.
- Integrated the actuators into a droplet generator setup for liquid jet excitation.
- Tested the frequency response and amplitude capabilities of the actuators.
- Assessed the performance in generating monodisperse droplets from a liquid jet.
Main Results:
- Rotary voice coil actuators reliably reproduce frequencies from 0 to 17 kHz and potentially higher.
- Actuators provide greater vibration amplitudes compared to typical loudspeakers used in similar setups.
- The system operates with significantly reduced noise levels.
- No specialized machining tools or external amplifying electronics are required for construction and operation.
Conclusions:
- Rotary voice coil actuators are a viable and advantageous replacement for loudspeakers as vibration sources in laboratory applications.
- The presented droplet generator design, using hard drive actuators, offers a simple, inexpensive, and effective method for producing monodisperse droplets.
- This approach democratizes the creation of specialized experimental apparatus, making advanced fluid manipulation more accessible.
