Thank you for your question. RFMicron’s positioning sensors (relative to metal) has this capability. Because our low-cost sensors do not require a battery, they are powered using radio frequency (RF) energy harvesting techniques commonly utilized by RFID tags and corresponding readers.
There are many dependencies based on the specific user application. For example, is the sensor being used to detect the proximity of two pieces of metal relative to each other, or one metal object relative to one insulating object? Other dependencies may include the sizes/thicknesses that are acceptable for the sensor and where the reader antenna may be placed. We are happy to discuss the specifics of your application by contacting our customer support team HERE.