Blood-mimicking delivery in polygonal structure of inner quadrupletip microneedle with valveless micro-pump

This paper presents a titanium quadrupletip micro-needle integrated with a micropump with different inner designs, length and diameter of the micro-channels to measure and maximize the velocity flow in the micro-needle as blood delivered into human body. Titanium is used as the material of the micro-needle which are also the common material in manufacturing of micro-needle. The advancement of micro-needle technologies is improved in penetrating human outermost skin, stratum corneum and further to human blood vessels. The micro-needles with channel inner design of circular, square, hexagon, and dodecagon with quadruple tip designs are drawn with inner diameter parameter of 150μm and 100μm with two different channel length which are 10mm and 25mm. The characteristics of blood delivery in geometrically changed inner designs affect the output velocity in microneedle when the micropump is operating. The results showed that, when it is pumped at 0.04m/s, the blood velocity improved by 5.6% than when the pump is increased by 30% of its capacity. This is due to the backflow generated in the micropump

Combined aerodynamic and electrostatic atomization of dielectric liquid jets

The electrical and atomization performance of a plane-plane charge injection atomizer using a dielectric liquid, and operating at pump pressures ranging from 15 to 35 bar corresponding to injection velocities of up to 50m/s, is explored via low current electrical measurements, spray imaging and phase Doppler anemometry (PDA). The work is aimed at understanding the contribution of electrostatic charging relevant to typical higher pressure fuel injection systems such as those employed in the aeronautical, automotive and marine sectors. Results show that mean specific charge increases with injection velocity significantly. The effect of electrostatic charge is advantageous at the 15-35 bar range and an arithmetic mean diameter D10 as low as 0.2d is achievable in the spray core and lower still in the periphery where d is the orifice diameter. Using the data available from this higher pressure system and from previous high Reynolds number systems [1], the promotion of primary atomization has been analyzed by examining the effect that charge has on liquid jet surface and liquid jet bulk instability. The results suggest that for the low charge density Qv~2C/m3 cases under consideration here, a significant increase in primary atomization is observed due to a combination of electrical and aerodynamic forces acting on the jet surface, attributed to the significantly higher jet Weber number (Wej) when compared to low injection pressure cases. Analysis of Sauter mean diameter (SMD) results show that for jets with elevated specific charge density of the order QV~6C/m3, the jet creates droplets that a conventional turbulent jet would, but with a significantly lower power requirement. This suggests that “turbulent” primary atomization, the turbulence being induced by electrical forces, may be achieved under injection pressures that would produce laminar jets