Bioengineered veins can benefit humans needing bypass surgery, dialysis, and now, in the treatment of varicose veins. The implant of this vein in varicose veins has significant advantages over the conventional treatment methods. Deep vein thrombosis (DVT), vein patch repair, pulmonary embolus, and tissue-damaging problems can be solved with this implant. Here, the authors have proposed biomedical microdevices as an alternative for varicose veins. MATLAB and ANSYS Fluent have been used for simulations of blood flow for bioengineered veins. The silver based microchannel has been fabricated by using a micromachining process. The dimensions of the silver substrates are 51 mm, 25 mm, and 1.1 mm, in length, width, and depth respectively. The dimensions of microchannels grooved in the substrates are 0.9 mm in width and depth. The boundary conditions for pressure and velocity were considered, from 1.0 kPa to 1.50 kPa, and 0.02 m/s to 0.07 m/s, respectively. These are the actual values of pressure and velocity in varicose veins. The flow rate of 5.843 (0.1 nL/s) and velocity of 5.843 cm/s were determined at Reynolds number 164.88 in experimental testing. The graphs and results from simulations and experiments are in close agreement. These microchannels can be inserted into varicose veins as a replacement to maintain the excellent blood flow in human legs.
8 August 2017 in Journal of Science: Advanced Materials and Devices
In this work, the replication-based microcontact printing method has been presented to study the deformation effect of different printing times and printing pressures on the microcontact printed structures. Cost-effective microcontact printing channels of self-assembled monolayers of alkanethiol have been prepared on gold surface. The alkanethiol inking the polydimethylsiloxanes stamp effectively forms the self-assembled monolayers on the noble gold surface that protects the metal against etchant solution and thereby forms channel-like structures. To address the deformation issue, variations in the printing time in the range of 30 s–60 min and the printing pressure ranging from 840 to 4200 Pa have been studied. The estimation of differing the channel width and channel space with varying printing time and pressure shows the best resolution structures printed under minimal printing time at atmospheric pressure.