Research Areas

Flow Control Based on Microfluidics & Nanofluidics

Advanced Flow Visualization Techniques

Biofluid and Biomimetic Technology

Blood-sucking mechanism of a female mosquito
Micro-PIV system
Schematic diagram of the synchrotron X-ray micro-imaging technique
Systaltic motion of the two pumping organs of a female mosquito during sucking of diluted iodine solution
Typical flow velocity inside the food canal of a female mosquito and the corresponding volume variation of the two pumping organs
A cyclic volume variation of the two pumps, CP and PP, of (A) a female mosquito and (B) a male mosquito
Pump system segmented from 3D reconstructed head of a female mosquito and corresponding live synchrotron X-ray images. (A), (B) static state and (C), (D) expansion state of the CP and the PP.
  • Intake flow rate inside the food canal of a female mosquito
  • The corresponding acceleration
  • Hypothesized model for the volume variation of the two pumps.

The two pump organs of a mosquito operate in a well coordinated manner with a certain phase shift for sucking blood efficiently.

Liquid-feeding strategy of a butterfly

Experimental set-up used for micro-PIV measurements of flow in butterfly proboscis
Experimental set up for (a) 2D synchrotron X-ray images and (b) micro -CT
3D reconstructions of a butterfly’s pump system acquired by micro-CT
The dynamic motions of the butterfly pump system
  • SEM image of a coiled butterfly proboscis.
  • Optical image of the tip of the straightened proboscis. In the tip region, the proboscis has a slit like structures.
  • The trace particles image and velocity field around the tip of the proboscis. The liquid is sucked into the slit structures.
Butterflies feeding on wet surface possess a brush structure at the tip.
The brush + intake slit combined structure increases uptake of liquid from the wet surface.

Butterflies have developed effective strategies for compensating the disadvantages of a long proboscis and adapting to liquid sources.

Development of a biomimetic micropump

Two-pump system and blood-sucking model of a female mosquito
Concept of the serially connected two pumping chambers and its phase control method inspired by a female mosquito
(a) Type 1 micropump. (b) Type 2 micropump. The pumping chambers of the type 2 micropump have different sizes. (c) The cross section of the two-pump micropump. (d) Geometry of diffuser.
Schematic diagram of the experimental setup consisting of the fabricated micropump and the measurement system.
  • Volume flow rate of the type 1 micropump with respect to operating frequency.
  • Optimal phase shift giving the maximum volume flow rate with respect to operating frequency.
  • Volume flow rate of the type 2 micropump measured with variation in the phase shift.
  • Variation in the optimal phase shift with respect to operating frequency.

The pumping performance of the serial-connected two micropumps is heavily dependent on the phase shift. The optimum phase shifts of both micropumps are180◦ out-of-phase at high operating frequencies.

Comparison of blood-sucking strategies of Anopheles sinensis and Aedes togoi

Sitting postures and 3D morphological structures of head of Anophelesis sinensis, human malarial vector mosquito, and Aedes togoi
Cyclic volume variations of the two pumps, CP and PP, of
  • Anophelesis sinensis and
  • Aedes togoi
Phasic variations in flow rates inside the food canal of Anophelesis sinensis and Aedes togoi
Comparison of the stroke volume and ejection volume ratio between Aedes togoi and Anophelesis sinensis

Two mosquitoes exhibit distinct differences in the range of flow rates and the ratio of ejection volume which can affect transmission of diseases.