A sensor is a device, module, or subsystem whose purpose is to detect events or changes in its environment and send the information to other electronics, frequently a computer processor. A sensor is always used with other electronics, whether as simple as a light or as complex as a computer.
see Tactile sensor.
Sensor Technology Embedded in Stents: A Potential New Approach to Continuous Monitoring for in Stent Stenosis, Thrombosis, and Beyond 1).