A surgical robotic arm includes a first link and a second link, wherein at least one of the first link or second link is movable relative to each other. The surgical robotic arm also includes a sensor assembly coupled to at least one of the first link or the second link. The sensor assembly includes a force sensing resistor assembly configured to measure force and an interface member disposed over the force sensing resistor assembly, the interface member configured to engage the at least one force sensing resistor assembly due to the interface member contacting an obstruction.