Problem of current monitoring in microfluidics

[frenchero]

Hi!
I want to characterize microfluidic device with nanochannels and i choosed to use current monitoring. The nanochannel is basically linking to resevoirs (microchannels with electrodes. At one electrodes I have the voltage and on the outlet of my chip I put a resistance. By mesuring the vltage of my resistance I have directly acces to the current in my chip.
But I have a little problem
I preparde a buffer which conducitivty is 9.4e-4 S/m. Knowing that I have 9500 500µm long nanochannels in parallel I should have for 100V voltage a current of about 1e-2µA. But I mesure a current of 30µA! I also tried to introduce Dionized water in my nanochannel and I have the same result! So apparently something iraise the current intensity and is hiding the current I want to monitor.
Would someone have an idea of what could explain this high current result?

Thank you a lot!

 

[_coyote_]

The high current result could be caused by several factors. The first one is that the nanochannels may not be completely sealed and the buffer solution may have leaked out, causing a decrease in resistance and an increase in current. Another possible factor could be contamination of the electrodes, which could cause an increase in electrical conductivity and thus an increase in current. Additionally, it is possible that the nanochannels are not completely uniform, and some channels may be wider than others, causing a decrease in resistance and an increase in current. Finally, the buffer solution may not be completely homogeneous, and there could be areas of higher or lower conductivity, which could also lead to a higher current result.

 

[oswaler]

Hello,

The problem you are experiencing with current monitoring in your microfluidic device is likely due to several factors. First, the conductivity of your buffer may not be accurately measured or may vary throughout the device. This can lead to discrepancies in the expected current values. Additionally, the nanochannels may not be uniformly sized or may have defects that can affect the flow of current. It is also possible that there is leakage or short-circuiting occurring within the device, causing an increase in current. Another potential issue could be the electrodes themselves, as they may not be properly calibrated or may have a high resistance which can affect the current readings.

To address these issues, it would be beneficial to carefully calibrate your device and ensure that all components are functioning properly. This may involve using a different buffer solution with a known conductivity, checking the integrity of the nanochannels, and verifying the accuracy of the electrodes. Additionally, it may be helpful to consult with other researchers in the field or seek advice from experts who have experience with microfluidic devices and current monitoring. By troubleshooting and addressing these potential sources of error, you should be able to obtain more accurate and consistent current measurements in your device.