—Droplet generating in an immiscible liquid is the
core technology of the droplet based biochemistry analysis. A
new method, not based on micro-fluidic chip, is here proposed
to produce micro scale aqueous phase droplets in oil phase
liquid. The principle of the droplet generator is to actuate a
hollow PZT stack by a signal generator and a voltage
amplification to provide an enough pulse inertia force for a
glass micro-nozzle and aqueous phase liquid inside to eject
droplets. The minimum diameter of the produced spherical
droplets is below 10 μm, which is below 1 pL. The range of
droplets formation frequency is 2 Hz~50 Hz. A fused silica
capillary is used to store the produced droplets by a designed
low-pressure suction apparatus and the distance between the
neighboring droplets is controlled by the low-pressure value.
The proposed method in this article may be a promising
approach for droplet-based single cell encapsulating and
—Microfluids, emulsions, pulse inertia force,
Hongcheng Wang and Zhendong Dai are with the Institute of
Bio-inspired Structure and Surface Engineering, Nanjing University of
Aeronautics and Astromautics, Nanjing, CO 210016, China (e-mail:
Weiyi Zhang and Jia Liu are with the School of Mechanical Engineering,
Nanjing University of Science and Technology, Nanjing, CO 210094, China
(e-mail: firstname.lastname@example.org, email@example.com).
Cite: Hongcheng Wang, Weiyi Zhang, Jia Liu, and Zhendong Dai, "Formation and Storage of on Demand Water-in-oil Picoliter Droplets Actuated by Microfluidic Pulse Inertia Force," International Journal of Materials, Mechanics and Manufacturing vol. 3, no. 3, pp. 187-190, 2015.