Table 3.

Advantages and limitations of resistive heating, channels, and optical heating to generate the temperature gradients in micro-scale devices.

Methods	Advantages	Limitations
resistive heating		heat sink needed
	direct implementation	temperature controlled close to cell
	large T-gradients possible	additional effects (e.g., dielectrophoresis)
		expensive
channels	conventional fabrication	lower temperature gradients
	heat sink not required	external thermostat required
optical heating	large T-gradients possible	transparent material required
	free manipulation	heat sink needed
		temperature depends on sample absorption