A sensor interface is disclosed including a flexible substrate in which are embedded sensors for measuring physical parameters such as temperature, displacement, velocity, acceleration, stress, strain, pressure and force present between objects such as a railcar bearing and a truck side frame. The substrate is positioned between the objects of interest Electronic components such as a data processing unit, a data storage device, a communication device and a power source may also be embedded within the substrate. The electronic devices communicate with one another and the sensors to process signals generated by the sensors indicative of the parameters being measured.