Abstract
Accumulation of particles in a high concentration on a microchannel wall is a common phenomenon in a colloidal fluid. Gradual accumulation/deposition of particles can eventually obstruct the fluid flow and lead to clogging, which seriously affects the accuracy and reliability of nozzle-based printing and causes damage to the nozzle. Particle accumulation in a 100 μm microchannel was investigated by light microscopy, and its area growth in an exponential format was used to quantify this phenomenon. The effects of the constriction angle and alginate concentration on particle accumulation were also studied. In order to reduce the clogging problem, an acoustic method was proposed and evaluated here. Numerical simulation was first conducted to predict the acoustic radiation force on the particles in the fluid with different viscosities. Interdigital transducers (IDTs) were fabricated on the LiNbO3 wafer to produce standing surface acoustic waves (SSAW) in the microchannel. It was found that the actuation of SSAW can reduce the accumulation area in the microchannel by 2 to 3.7-fold. In summary, the particle accumulation becomes significant with the increase of the constriction angle and fluid viscosity. The SSAW can effectively reduce the particle accumulation and postpone clogging.
Highlights
Inkjet printing has been used widely in recreating a digital image by propelling droplets onto paper, plastic, or other substrates using either continuous or drop-on-demand technology since the late1970s [1]
Its advantages include low cost and noise, and high resolution. This versatile computer-aided tool can be applied in many manufacturing fields with high-throughput, such as the fabrication of functional and structural materials [2], all-polymer transistor circuits [3], organ/tissue printing [4], and recombinant proteins microarrays [5]
The clogging problem would result in non-uniformity of the printed part, loss of material, long printing time, and excessive time devoted to printing quality, but it is difficult to predict
Summary
Inkjet printing has been used widely in recreating a digital image by propelling droplets onto paper, plastic, or other substrates using either continuous or drop-on-demand technology since the late1970s [1]. Its advantages include low cost and noise, and high resolution. This versatile computer-aided tool can be applied in many manufacturing fields with high-throughput, such as the fabrication of functional and structural materials [2], all-polymer transistor circuits [3], organ/tissue printing [4], and recombinant proteins microarrays [5]. Accumulation and deposition of particles usually occur in nozzle-based printing, especially in small nozzles for extrusion of fine drops. This phenomenon is a progressive process and may cause an obstruction of the upstream fluid flow, either temporarily or permanently, and lead to clogging. The corresponding value of pure water at room
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
