Diagnosis of Various Biofluid Flow Phenomena and Biomimic Research

Biological flows are vital for the conservation of life and indispensable commodity of living organisms. Morphological structures of living organisms and biological flow phenomena in nature have been evolved through a long history. The basic biophysics of several biofluid flow phenomena and the hidden secrets of nature such as blood flow in chicken embryos, blood sucking of mosquitoes, and sap flows in plants have been investigated experimentally by using advanced flow visualization techniques, such as X-ray PIV (particle image veocimetry), holographic PTV (particle tracking veocimetry), time-resolved micro-PIV, etc. Biological samples include insects (blood-sucking mosquitoes, liquid-feeding butterflies), fishes (zebra fish, planktons), animals (blood flows in chicken embryos or rats) and plants (sap flow in xylem vessels of rice or Arabidopsis). Gold nanoparticles developed as tracer particles transmit membranes of organisms without destroying the surrounding tissues. Detailed understanding on these biofluid flow phenomena are helpful to develop creative nature-inspired technologies for practical applications in biomedical science, microfluidics and renewable energy, etc. For example, a micropump consisting of serial-connected two-pump chambers and three diffuser elements was developed based on the revealed blood-sucking mechanism of a female mosquito. When the two pump chambers are operated in a well coordinated manner with a certain phase shift, the bio-inspired pump exhibits a good pumping performance, as appeared in the blood-sucking mosquitoes. The nature-inspired micropump would be utilized in various bio-chips as a liquid-phase sample supplying system. In addition, another bio-inspired micropump that can produce a large pressure gradient was developed by bio-inspiring a liquid-feeding butterfly through a long proboscis.