Paper Title
Electrical-Induced Flow in Pva/Aa Hydrogel Microchannels

Abstract
The need to study flow through micropump has led to wide investigation on microfluidic devices. Although several investigations have been reported on different microfluidic, this work was design to investigate electrical induced flow in a hydrogel microchannel at varying hydraulic diameters. A semi interpenetrating polymeric network method was used to synthesize hydrogel, which was a crosslink of polyvinyl alcohol and acrylic acid. Other reagent used to form at varying proportions are hydrogel are (HCL, (NH_4)〖_2 S〗_2 O_8 ,C_5 H_8 O_2 and C_6 H_16 N_2 ). Polymeric hydrogels were formed at a ratio of 39 : 61%,50 : 50% and 60 : 40% polyvinyl alcohol to acrylic acid. Micromechanical characterization was conducted on the polymeric hydrogel. The pre-polymer solutions of hydrogel were poured on PMMA mold to form a microchannel of hydraulic diameter 800µm, 1000µm, 1200µm and 1400µm respectively. Flow investigation was carried out with water as working fluid at an applied voltage of 2V to 22V,with microchannel power consumption of (0.80W-165W) for 800µm,1000µm,(1.80W-176W) for 1200µm and (1.98W-180.40W) for 1400µm hydrogel microchannel respectively. The hydrogel Microchannel performance was compared to literature. The 39:61% PVA/AA crosslink hydrogel under applied load of 5.8210N deformed at 0.60260mpa and break at 0.42152 MPa to give a young modulus of (-0.80 to 1.01)〖N/M〗^2.The 50:50% crosslink PVA/AA hydrogel under applied load 2.37762N deformed at 0.24441MPa and break at 0.08213 MPa resulting in a young modulus (-7.0 to 1〖.0)N/M〗^2.The 60:40% PVA/AA hydrogel crosslink with distill and ionized water under applied load 3.41912N,deformed at 0.05422mpa,result in young modulus (-4.0 to 1.0)〖N/M〗^2; and at applied load of 2.14706N,breaking point was 0.00587mpa result in young modulus (-3.50 to 1.10) 〖N/M〗^2. The performance efficiency for hydrogel microchannel of hydraulic diameter 800µm,1000µm,1200 µm and 1400 µm with different crosslink ratio were (0.00% to 32.96%)PVA/AA 39:61%,(0.00% to 26.22%)PVA/AA 50:50%,(0.00% to 217.3%)PVA/AA 60:40% and (0.00% to 349.48%)PVA/AA 60:40% hydrogel crosslink with ionized water at a flow rate of (0.00ml/min to 0.18ml/min)800µm,(0.00ml/min to 0.32ml/min)1000µm,(0.00ml/min to 0.47ml/min)1200µm and (0.00ml/min to 0.50ml/min)1400µm. This study established that with increase in hydraulic diameter of PVA/AA hydrogel microchannel there will be increase in flow rate and consumed low power. The hydrogel microchannel can also serves as an alternative to micropump which could be applicable for design of feeder systems for cleft deformities. Keywords- Hydrogel, Microchannel, Microfluidic, Polyvinyl Alcohol, Acrylic Acid, Polymethylmetalcrylate