This study elaborates on the design, fabrication, and data analysis details of SPEED, a recently proposed smartphone-based digital polymerase chain reaction (dPCR) device. The dPCR chips incorporate partition diameters ranging from 50 μm to 5 μm, and these partitions are organized into six distinct blocks to facilitate image processing. Due to the superior thermal conductivity of Si and its potential for mass production, the dPCR chips were fabricated on a Si substrate. A temperature control system based on a high-power density Peltier element and a preheating/cooling PCR protocol user interface shortening the thermal cycle time. The optical design employs four 470 nm light-emitting diodes as light sources, with filters and mirrors effectively managing the light emitted during PCR. An algorithm is utilized for image processing and illumination nonuniformity correction including conversion to a monochromatic format, partition identification, skew correction, and the generation of an image correction mask. We validated the device using a range of deoxyribonucleic acid targets, demonstrating its potential applicability across multiple fields. Therefore, we provide guidance and verification of the design and testing of the recently proposed SPEED device.

Bioinspired Engineering and Biomechanics Center Xi'an Jiaotong University Xi'an 710049 PR China

Central European Institute of Technology Brno University of Technology Purkyňova 123 61300 Brno Czech Republic

Institute of Biology and Medical Genetics; 1st Faculty of Medicine Charles University and General University Hospital of Prague Albertov 4 12800 Prague Czech Republic

ITD Tech S R O Osvoboditelu 1005 735 81 Bohumín Czech Republic

Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace; School of Mechanical Engineering Northwestern Polytechnical University 127 West Youyi Road Xi'an Shaanxi 710072 PR China

School of Marine Science and Technology Northwestern Polytechnical University Xi'an Shaanxi 710072 PR China

The Key Laboratory of Biomedical Information Engineering of the Ministry of Education; School of Life Science and Technology Xi'an Jiaotong University Xi'an Shaanxi 710049 PR China

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Microfluidics chips fabrication techniques comparison