. Author manuscript; available in PMC: 2024 Aug 1.

Published in final edited form as: Nat Protoc. 2023 Jul 19;18(8):2441–2458. doi: 10.1038/s41596-023-00844-5

Table 3 |.

Troubleshooting table

Step	Problem	Possible reason	Solution
2	White residue formed on the SU-8 pattern	The SU-8 photoresist is not fully developed	For mild residue issue, immerse the SU-8 patterned substrate into SU-8 developer for 30 s and dry the substrate to remove the white residue. For severe residue issue, immerse the SU-8 patterned substrate into acetone for 30 s and dry it with an air stream
8	Pattern distortion after development of the SPR-3012 photoresist	The photoresist is under-exposed or over-exposed	Measure the width of the developed pattern under the microscope. Increase or decrease the exposure time based on the measured results to achieve accurate pattern. Restart the process from step 7
19	Defect in bonding between the LiNbO₃ substrate and the microfluidic chamber	Mishandling in the APTES coating and plasma treatment process	Remove the defect PDMS chamber from the LiNbO₃ substrate with a razor blade. Clean the PDMS residue and dry it with an air stream. Recycle the LiNbO₃ substrate and restart the process from step 14
20	Short circuit of the interdigital transducers	Defect in electrode fabrication or in silver epoxy process	Examine all the electrodes under an upright microscope. For the electrode damaged due to the fabrication process, the device cannot be used and recycled. For silver epoxy induced short circuit, scratch the epoxy to disconnect the shorted electrodes.
36	Air bubble trapped in the microfluidic chamber	Bubble trapped in the PBS, needle, or syringe	For bubble trapped in the needle and syringe, carefully remove air bubbles by tapping and pushing the syringe before injecting the PBS. For bubble already trapped in the microfluidic chamber, infuse the PBS with higher infusion speed (300 μl min⁻¹) to squeeze out the air droplets.
64	Cell residue in the microfluidic chamber	Adherent cell residue on the PDMS walls or the LiNbO₃ substrate	Inject ethanol with 5 ml syringe while sonicating the device to flush the microfluidic chamber for 2 min. Repeat this step if there is any residue detected under the microscope.