A wireless, connection-free, open circuit technology can be used for developing electrical devices like sensors that need no physical contact with the properties being measured. At the core of the technology is the SansEC (Sans Electrical Connections) circuit that is damage-resilient and environmentally friendly to manufacture and use.

This technology uses a “floating electrode,” or an electrically conductive object not connected to anything by wires, and is powered through a wireless device. This system uses inductor-capacitor thin-film open circuit technology. It consists of a uniquely designed, electrically conductive geometric pattern that stores energy in both electric and magnetic fields, along with a floating electrode in proximity to the open circuit. When wirelessly pulsed from the handheld data acquisition system, the system becomes electrically active and develops a capacitance between the two circuit surfaces. The result is a device that acts as a parallel plate capacitor without electrical connections. When applied to strain measurements, the sensor has been demonstrated to have displacement and strain resolution of 3.9 μm and 0.6 με, respectively.

A magnetic field response measurement acquisition device is used to provide power and, in the case of a sensor application, to acquire physical property measurements from them. This new approach using open circuits enables applications for sensors for axial load force, linear displacement, rotation, strain, pressure, torque, and motion sensing, as well as unique designs for a wireless keypad or wireless rotational dial, or for energy storage.

This work was done by Stanley E. Woodard of Langley Research Center and Bryant D. Taylor of ATK Space Systems. LAR-17711-1/958-1