In order to place sensors or electronics in very high temperature environments, new materials and methods for interconnection are required. A comparative study between different electrical interconnection methods for very high operation temperatures (500 °C - 800 °C) is presented. Thermo-mechanical simulations and characterization of samples of the interconnection types during high temperature exposure are presented. The results of the thermo-mechanical simulations showed that stresses are low in a connection system based on liquid interconnection. This system, however, proved to be difficult to realize due to problems with oxides and sealing of the metallic liquid. Modeling of an interconnection based purely on mechanical pressure without any solder or metallic bond showed high stress. This was also confirmed during high temperature exposure where the connection failed. High stress was also predicted for an interconnection based on nano-Ag paste. The high temperature tests, however, showed promising results at 800 °C for over 100 hours. © 2011 IEEE.