Abstract: A retro-reflective identification tag capable of modulating an optical signal whereby to support bi-directional communication with an associated remote optical interrogation device. The tag comprises a MOEMS modulating layer over a retro-reflective substrate, giving the tag a wide angle of effective operation. The tag modulator may optionally be switched on only responsive to detection of a precursor beam from the interrogation system in order to save power. The interrogation device may make use of multiple optical wavelengths for communicating with the tag.

Abstract: A molecular single electron transistor (MSET) detector device (14) is described that comprises at least one organic molecule (87) connecting a drain electrode (84) and a source electrode (82). In use, said at least one organic molecule (87) provides a quantum confinement region. At least one analyte receptor site (90, 92) is provided in the vicinity of said at least one organic molecule (87) that bind molecules of interest (analytes). A fluid analyser (2) is also described that includes the MSET detector, a pre-concentrator (4) and a fluid gating structure (6). The fluid gating structure (6) is arranged to selectively route fluid from the pre-concentrator (4) to either one of the detector (14) and an exhaust port (12). The pre-concentrator (4), fluid gating structure (6) and detector (14) are each formed as substantially planar layers and arranged in a stack or cube.

Abstract: A magnetic field sensor device (2) is described that comprises an oscillatory member (8) and current control means (6). The current control means (6) is arranged to pass an alternating current (AC) along at least first (10) and second (12) current paths provided through the oscillatory member (8) and is arranged to provide magnetic gradiometer mode operation (i.e. to measure magnetic field gradient) in which current flow through the first current path (10) is in substantially the opposite direction to current flow through the second current path (12). The current control means (6) can also prove magnetometer mode operation (i.e. to measure magnetic field strength). The magnetic field sensor (2) may be used in a compass.

Abstract: A micro electromechanical system (MEMS) switch includes a fixed contact (24) and a moveable contact (35) on an armature (30). The switch has electrodes (22, 34) associated with both the fixed and moveable contacts for providing an electrostatic switch operation and piezoelectric material with associated electrodes (36, 40) for bending the armature upon application of an electric voltage and providing an initial piezoelectric switch operation followed by electrostatic switching and clamping. The armature is of curved shape which is bent away from the fixed contact when in a switch open condition with zero applied voltage. This gives a large, e.g. 3 pm, switch gap in an OFF state which is reduced by piezoelectric operation suitable for electrostatic switch closing. A curved condition is provided by varying strain across the armature thickness, and is produced during manufacture of the switch.

Abstract: A resonant magnetometer comprises a substrate having a member and circuitry for passing an alternating current (AC) through the member. The magnetometer is characterized in that a driver is also provided to impart a magnetic field independent oscillatory force to the member. Disclosed is a micro-electro mechanical systems (MEMS) implementation of a magnetometer.

Abstract: A micro-electromechanical system (MEMS) comprises a substrate incorporating an oscillatory ring, forcing electrodes for driving the ring into resonance, and sensing electrodes providing an electrical output signal dependent on oscillation of the ring as a result of such forcing and any externally applied force. A positive feedback circuit is provided for feeding back a signal dependent on the output signal of the sensing electrodes to the forcing electrodes in order to sustain oscillation of the ring. The use of positive feedback to drive the forcing electrodes in order to sustain oscillation of the ring is highly advantageous in such an application since it produces a system which exhibits very low phase noise of a magnitude considerably less than the phase noise experienced in use of a phase-lock loop circuit to sustain oscillation.

Abstract: An infra-red detector (10) comprises a detector region (38) and a collector region separated by a barrier region. Operation of these regions is controlled by potentials applied to respective gate electrodes (30, 34, 32), insulated from the detector, barrier and collector regions by an insulating oxide layer (36). The detector, barrier, and collector regions may be arranged on a silicon substrate (24). In operation, photo-excited electrons are generated in the detector region and these cross the barrier region for readout from the collector region.