Abstract
A chip device for a thermally cycled reaction includes a looped pressure channel divided into a plurality of angularly oriented sub-channels, and a looped fluid channel substantially corresponding to and disposed below the looped pressure channel. The fluid channel has a plurality of temperature zones below the respective sub-channels. A looped membrane is disposed between the fluid channel and the pressure channel. The membrane is inflated or deflated by the pressure in the sub-channels so as to block or unblock the fluid channel partially or completely. A fluid sample is movable by the membrane to an unblocked part of the fluid channel from a blocked part of the fluid channel so that the fluid sample may be circulated repeatedly along the fluid channel.