Design of multiple reaction systems for genetic analysis

Heat-transfer considerations significantly constrain design of multiple reaction microdevices. We present a new methodology for design and fabrication of multiple reaction systems using the concept of heat integration. Heat integration is a design concept that strikes a balance between complete thermal isolation of individual thermal operations and power consumption in a multiple reaction device. It relies on the use of steady-state temperature gradients developed in the substrate, by the actuation of a single reaction chamber, to initiate several reactions at progressively lower temperatures. The use of thermal gradients in this manner eliminates power requirements to heat individual reactions, active temperature control of "passive" reaction chambers and power requirement for cooling. Complete thermal isolation on the other hand, requires higher power for device cooling but, unlike the case of heat integration, geometry of component placement is relatively unconstrained.