Handheld and 'Turnkey' 3D printed paper-microfluidic viscometer with on-board microcontroller for smartphone based biosensing applications.

Affiliation

Puneeth SB(1), Goel S(2).
Author information:
(1)MEMS, Microfluidics and Nanoelectronics Lab, Department of Electronics and Electrical Science, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Hyderabad, India, 500078.
(2)MEMS, Microfluidics and Nanoelectronics Lab, Department of Electronics and Electrical Science, Birla Institute of Technology and Science, Pilani, Hyderabad Campus, Hyderabad, India, 500078. Electronic address: [Email]

Abstract

Herein, Microfluidic Paper-based Analytical Devices (μPAD) strips, also called microstrips, have been fabricated using a fused-deposition modeling (FDM) based 3D printer. A polycaprolactone (PCL) filament on a chromatography paper was harnessed to create hydrophobic boundaries of a microchannel. A pair of screen-printed electrodes, with known separation, were integrated on the microchannel to measure the time taken for fluid automatically. A mini electronic sub-system, amenable to connect with an android smartphone, consists of an easily programmable microcontroller, Bluetooth module and voltage booster circuit. The pluggable-and-playable disposable microstrip was utilized to measure the viscosity of various biological samples with an accuracy of >92% with respect to a benchtop viscometer. In particular, the protein denaturation of Bovine Serum Albumin (BSA) and Lysozyme, and viscosity variation of human saliva have been observed. With a competency to measure the viscosity between 0.5 cP to 10 cP, platform cost of