Table 2.

Summary of technical details in different CFPS system. Citations indicate where more information about the systems in the context of cell-free can be found.

Physical signal	Key elements	Cell-free system	Reaction format	Volume	Pros	Cons	Ref.
Light	YF1/FixJ	E. coli extract	Batch; One compartment	20 μL	Abundant components responding to different wavelengths	Slow signal relay and reversal rates; Poor portability	[5]
	EL222	E. coli extract	Batch; One compartment	25 μL	Good portability; Fast response	Limited response wavelength	[17]
	Azobenzene-tethered promoter	PURE	Batch; One compartment	–	Avoiding complex protein interactions	Tedious preparation process	[30]
Temperature	RNAT	PURE	Batch; One compartment	–	Flexible and varied means of temperature control	Low expression	[18]
Electric field	DNA brush on a chip	PURE	Batch; Fixed in compartment on a chip	Compartment: R = 35 μm; H = 3 μm	Novel manipulation of cell-free expression	Reduced component performance by electrothermal effect	[19]
	DMF board	E. coli extract	Batch; Multiple droplet compartments	20 μL	Remoted control of cell-free expression	Limited control scale	[42]
Magnetic force	Magnetic beads coated with DNAs	E. coli extract	Batch; One compartment	24 μL	Simple control method and spatiotemporal principle	The attachment effectiveness of DNA on magnetic beads	[20]