Cross‐Linked Gold Nanoparticle Composite Membranes as Highly Sensitive Pressure Sensors

In this article, highly sensitive differential pressure sensors based on free‐standing membranes of cross‐linked gold nanoparticles are demonstrated. The nanoparticle membranes are employed as both diaphragms and resistive transducers. The elasticity and the pronounced resistive strain sensitivity of these nanometer‐thin composites enable the fabrication of sensors achieving high sensitivities exceeding 10−3 mbar−1 while maintaining an overall small membrane area. Furthermore, by combining micro‐bulge tests with atomic force microscopy and in situ resistance measurements the membranes’ electromechanical responses are studied through precise observation of the concomitant changes of the membranes’ topography. The study demonstrates the high potential of free‐standing nanoparticle composites for the fabrication of highly sensitive force and pressure sensors and introduces a unique and powerful method for the electromechanical investigation of these materials. The fabrication of free‐standing membranes consisting of inorganic/organic nanoparticle composites allows for coupling their optoelectronic properties to their mechanical characteristics. In this article, highly sensitive resistive differential pressure sensors benefiting from the elasticity and tunneling‐based strain‐sensitivity of these new materials are reported. Further, a unique and powerful technique for their electromechanical characterization is presented.