Thick-film based multistage thermoelectric micro cryogenic coolers (MTMCCs) demonstrate versatility and efficiency needed for cooling devices that require cryogenic temperatures at specific locations . Micro cryogenic coolers that are able to create cryogenic temperature environments at targeted regions essential for device function allow for a wide range of military and scientific applications such as Infra Red (IR) detectors and lasers, low noise amplifiers, and scanning probe microscopes.
Existing technologies that are capable of reaching cryogenic temperature are efficient at macroscale; however, they are difficult to scale down to the microscale (around 20 microns), and their efficiency significantly drops with size reduction. Current commercial multistage thermoelectric devices are based on stacking multiple thermoelectric coolers, which leads to their larger size - limiting the coolers applications. This technology fabricates multistage thermoelectric micro cryogenic coolers by building all the stages along the plane of a film such that all the stages can be fabricated together through the use of microfrabrication technologies. Furthermore, the technology uses the idea of hybrid micro-miniature stacking, using a miniature stage as the last stage of the system to provide maximum flexibility to the environment temperature The miniature stage has a much higher cooling power.
The technology is an innovative approach to the fabrication of multistage thermoelectric micro cryogenic coolers, and demonstrates their versatility through applications in IR detection. By creating p-type leg and n-type leg portion of two cooling stages, the p-n junctions are thermally and electrically coupled, and therefore, at least a portion of a current through one stage during operation is coupled to the other. The p-n junction element also forms a unitary thermoelectric structure that spans more than one stage of the cooler so that all the stages of a multistage thermoelectric cryogenic cooler can be fabricated together.
- Minimizes heat loss
- Improves device performance
- Smaller size
- Simplifies power supply