Correction to: Scientific Reports https://doi.org/10.1038/s41598-017-18826-5, published online 11 January 2018

This Article contains typographical errors.

In the Methods section,

“Impedance was measured and maintained between 120 and 180 kΩ by liquid volume adjustment (reducing volume increases impedance)”

should read:

“Impedance was measured and maintained between 120 and 180 Ω by liquid volume adjustment (reducing volume increases impedance)”.

In Table 1,

“Adjust volume to keep impedance between 120 and 180 kΩ”

should read:

“Adjust volume to keep impedance between 120 and 180 Ω”.