Electrical current for controlling fluid parameters in microchannels

A microfluidic device comprising:

• a substrate;
• a first microscale channel disposed within the substrate, the first microscale channel having first and second portions, the first portion comprising an elevated temperature region, the elevated temperature region having an increased electrical resistance therethrough, relative to other portions of the first channel, when an electrical current is applied through the first microscale channel;
• a sensor operably coupled to the first channel for determining a temperature of a fluid in at least the first portion of the first channel;
• and
• an energy source responsive to the temperature determined in the fluid in at least the first portion of the first channel.

A microfluidic system comprising:

• a substrate having at least first and second microscale channels, wherein a first portion of the second channel intersects the first channel at a first portion of the first channel;
• a sensor operably coupled to at least the first channel for determining a temperature of a fluid in at least the first portion of the first channel;
• and
• an energy source responsive to the temperature determined in the fluid in the first portion of the first channel, for applying a first electrical current through the at least first portion of the first channel to heat a fluid disposed within the first portion of the channel to a first elevated temperature.