Thermal cycling devices are provided. In one embodiment, a thermal cycling device includes a packed tube comprising an inlet portion defining an inlet and an outlet portion defining an outlet. The packed tube is provided in a double coil arrangement, wherein the double coil arrangement causes radially neighboring turns of the packed tube to have opposing flow directions therethrough. The thermal cycling device further includes a cooling device disposed axially adjacent to the packed tube, and a heating device disposed axially adjacent to the packed tube opposite the cooling device.
FEDERAL RESEARCH STATEMENT
 This invention was made with Government support under Contract No. DE-AC09-08SR22470, awarded by the U.S. Department of Energy. The Government has certain rights in the invention.