Table 2.

Channels: typical sizes of microchannel, gap size between cooling/heating channel and operating channel, contact materials, cooling/heating temperature, maximum temperature gradient, and reference.

Sample	Gap Thick-	Contact Material	Cooling/Heating	Max. $\mathbf{Grad}$  T	$\mathit{\nabla }\mathit{T}$/$\mathit{\nabla }\mathit{g}$	Principle	Ref.
Volume/$\mathsf{\mu }$L	Ness/mm		Temp. ${}^{\circ }$C	Temp. K/m
0.6	-	Stainless Steel	5/80	0.15$·{10}^5$	h/v	microscope	[43,45,59,76]
≪240	0.75	Cu, Sapphire	5–35/20–65	1.5$·{10}^5$	v/v	microscope	[55]
≪200	0.5	Cu, Sapphire	20/20–50	$1.55·{10}^5$	v/v	microscope	[56]
≪5	-	Cu/PMMA	25/25–45	$1.4·{10}^5$	v/v	microscope	[61]
45	1.29	Cu, Sapphire	22/27	0.16$·{10}^5$	h/v	TGC	[41,47]
940	-	Al	22.5/27.5	$0.1·{10}^5$	h/v	TGC	[58]
20–70	0.025–0.05	Au	5–80/5.3–80.3	$1.2·{10}^4$	h/v	beam deflection	[37,77,78]