Harnessing random micromeso-scale ambient energy is not only clean and sustainable, but it also enables self-powered sensors and devices to be realized. Here we report a robust and self-powered kinematic vector sensor fabricated using highly pliable organic films that can be bent to spread over curved and uneven surfaces. The device derives its operational energy from a close-proximity triboelectrification of two surfaces: a polytetrafluoroethylene film coated with a two-column array of copper electrodes that constitutes the mover and a polyimide film with the top and bottom surfaces coated with a two-column aligned array of copper electrodes that comprises the stator. During relative reciprocations, the electrodes in the mover generate electric signals of ±5 V to attain a peak power density of ≥65 mW m(-2) at a speed of 0.3 ms(-1). From our 86,000 sliding motion tests of kinematic measurements, the sensor exhibits excellent stability, repeatability and strong signal durability.

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Self-powered thin-film motion vector sensor

Self-powered triboelectric velocity sensor for dual-mode sensing of rectified linear and rotary motions

A Motion Vector Sensor via Direct-Current Triboelectric Nanogenerator

For detecting the position of a magnetic element having a field component zeroing in at least one point in space, typically in a plane, a plurality of elementary Hall-effect sensors are integrated side by side and aligned in a direction perpendicular to the zeroing field component and to the current flowing through the elementary sensors. The elementary sensor generating a zero output voltage therefore indicates the zero position of the field component and consequently the position of the magnetic element with respect to the position sensor, so that The outputs of the elementary sensors provide a quantized numeric code indicating the position of the magnetic element.

An integrated hall•effect apparatus for detecting the position of a magnetic element

A member having a magnet attached is moveable along a path which has an array of magnetic field sensors adjacent the path. Each sensor provides a bipolar output signal as the magnet passes. A plurality of sensors provide a plurality of output signals for a first position of the magnet. Electronic means fit the plurality of output signals to a first curve having a crossover point to determine the first position.

Position detection apparatus including a circuit for receiving a plurality of output signal values and fitting the output signal values to a curve

Apparatus for measuring small displacements, either linear or angular, employ a pair of spaced "barber pole" or other magnetic field sensitive elements (BP1, BP2) and a movable magnet (22, 31, 33...), in which the exact position of the movable magnet is determined from the voltages sensed at the two elements. The voltages are evaluated in a circuit which produces a rectangular voltage or equivalent, in which the mark space ratio equates to the position of the magnet between the two sensors.

Apparatus for measuring small displacements

At present, electronic controls and systems are in the process of becoming essential and integral parts of our vehicles whereas they were previously replacements for corresponding mechanical systems predominantly separately acting or fulfilling add-on functions. From this viewpoint, the electronic systems in the vehicle will be interconnected with each other to a much greater degree than was previously the case; for this reason, they must also be reclassified and subdivided. Accordingly, electronic signal-processing components, for example, which were previously located in central control units, will be moved to the periphery where they are mechanically and electrically integrated with the sensor or actuator directly at the point at which they are actually required (mechatronics). The varied advantages of such sensors which are also capable of digital communication by means of new connection systems (bus systems) can be seen in the concrete example of an ‘intelligent’ short-circuit-ring displacement sensor. The accuracy of this sensor can be increased considerably by simultaneously simplifying its design; the highly accurate measured signal can be transmitted in a digital form.

Mechatronic sensors in integrated vehicle architecture

A method of measuring distance, for example along a machine, measures the time a magneto-acoustic pulse takes to travel along a magnetic strip to reach the point defined by a magnet on a movable machine part, which magnet produces a variation of the magnetic properties of the strip at that point. In order to eliminate effects of temperature expansion of the strip, the time is measured for pulses from both ends of the strip to reach the point, and the two times (t1,t2) are used to calculate the distance independently of the expansion.

Distance measuring apparatus and method

A device and an evaluation process are proposed in which the output signals (50 to 56) of a sensor arrangement (9) are used for determining the position of the position indicator (44). The position of the position indicator (44) is obtained from a simple evaluation of the output signals (51 to 54) of two or four sequential sensors i - 1, to i + 2 (58 to 61), which form part of either a first or second row of sensors (11, 20). The twin-row sensor arrangement (11, 20) permits compensation for an interfering magnetic field, by the fact that the position of the position indicator (44) is determined by obtaining the arithmetic mean of the position as measured by the two rows of sensors (11, 20). A temperature sensor (41) is provided in addition to the individual sensors (12 to 15, 21 to 24). The temperature measured by the sensor system (9) provides, in addition to the single-dimensional position measurement in the direction of measurement (45), a facility for measuring the distance of the position indicator (44) from the sensor arrangement (9). The position sensors (12 to 15, 21 to 24) are magnetoresistive elements which are produced, together with the temperature sensor (41), on a substrate (10) by using thin-film technology.

Günter Gerlach

Papers

Apparatus for measuring small displacements

Mechatronic sensors in integrated vehicle architecture

Distance measuring apparatus and method

Device for contactless position measurement