Bear Engineering proposes to develop a simple, robust, extreme environment compatible, mechanical load cell to enable the control of contact forces for placement of sampling systems and instruments against target locations. The load cell will be used to provide preset preloads and dynamically control the reaction force to a platform upon which a sampling system or instrument is mounted. The novel device has been designed to work solely by mechanical means using spring preloaded electrical contacts to create 6, 9, 12 or 18 discrete load sensing levels, depending on design parameters. When any of the load thresholds has been reached, the corresponding electrical contact changes state from normally open or normally closed. The load cell is completely sealed and has similar size, shape and strain displacements as traditional strain gage load cells. It is expected that this new design will have a diameter ranging from 2 to 3 inches (depending on designed force level) and a thickness of about ½ to 1 inch. Strain displacement at full load is expected to be about 0.003 inch. For future Mars, Venusian or other planetary sampling missions, the robust load cell would be a key component in ensuring and maintaining proper contact with rocks or samples of interest and it will be developed to TRL 4 at the end of the proposed effort. A potential Phase 2 will advance the design to TRL 6.
