Certain examples are directed to an apparatus having a stretchable synthetic membrane material and series of patterned conductive or semiconductive sections. The stretchable synthetic membrane material may be provided with the series of patterned sections being integrated in or against the material (e.g., on similarly-configured robotic digits operating as a pair). One or more of these sections are electrically coupled to sensor circuitry which may also be secured to or embedded in the material. As the apparatus moves relative to an external object, various environmental parameters may be sensed via at least one sensor as the object and the digit(s) approach one another. Depending on how the sensor circuitry is configured, such parameters may include one or more of proximity, capacitance, temperature, impedance, contact with the object, and movement of the robotic member relative to the external object.