A mechanical resonator device. The resonator device includes a resonator element made of an elastic material under tensile stress and adapted for sustaining at least one oscillation mode; and a clamping structure supporting the resonator element. The clamping structure has a phononic density of states exhibiting a bandgap or quasi-bandgap such that elastic waves of at least one polarisation and/or frequency are not allowed to propagate through the clamping structure. The resonator element and the clamping structure are configured to match with a soft-clamping condition that elastic waves of polarisation and/or frequency corresponding to the at least one oscillation mode of the resonator penetrate evanescently into the clamping structure in a manner such as to minimize bending throughout the entire resonator device. Thereby, bending related loss may be minimized and the Q-factor of the mechanical resonator may be maximized.

A device (10) for monitoring strain of an elongate member (12) is deployed underwater. The device (10) comprises a first clamp (14) configured to embrace and couple to the elongate member (12) at a first axial location, a second clamp (16) configured to embrace and couple to the elongate member at a second axial location separated from the first axial location, and a sensor which is responsive to an angle between the first clamp and the second clamp.

An oral care system including an oral care device and a processor. The oral care device includes a head having cleaning elements and a vibrational sensor configured to determine vibrational data emitted by the oral care device in use. The processor is operably coupled to the vibrational sensor and is configured to: determine, based on the vibrational data, an applied pressure of the cleaning elements upon an oral cavity of a user; determine an optimal pressure associated with the oral cavity of the user and a non-optimal pressure associated with the oral cavity of the user; and based on the applied pressure of the cleaning elements upon the oral cavity being substantially the non-optimal pressure, cause the applied pressure of the cleaning elements upon the oral cavity to be substantially the optimal pressure.

An oral care system including an oral care device and a processor. The oral care device includes a head having cleaning elements and a vibrational sensor configured to determine vibrational data emitted by the oral care device in use. The processor is operably coupled to the vibrational sensor and is configured to: determine, based on the vibrational data, an applied pressure of the cleaning elements upon an oral cavity of a user; determine an optimal pressure associated with the oral cavity of the user and a non-optimal pressure associated with the oral cavity of the user; and based on the applied pressure of the cleaning elements upon the oral cavity being substantially the non-optimal pressure, cause the applied pressure of the cleaning elements upon the oral cavity to be substantially the optimal pressure.

A sensor with a mechanical waveguide may be characterized using test ultrasonic signals to generate a baseline signature, and the baseline signature may later be used to detect faults in the sensor.

A sensor with a mechanical waveguide may be characterized using test ultrasonic signals to generate a baseline signature, and the baseline signature may later be used to detect faults in the sensor.

A tracking system for tracking a marker device for being attached to a medical device is provided, whereby the marker device includes a sensing unit comprising a magnetic object which may be excited by an external magnetic or electromagnetic excitation field into a mechanical oscillation of the magnetic object, and the tracking system comprises a field generator for generating a predetermined magnetic or electromagnetic excitation field for inducing mechanical oscillations of the magnetic object, a transducer for transducing a magnetic or electromagnetic field generated by the induced mechanical oscillations of the magnetic object into one or more electrical response signals, and a position determination unit for determining the position of the marker device on the basis of the one or more electrical response signals.

Hundreds of thousands of concrete bridges and hundreds of billions of tons of concrete require characterization with time for corrosion. Accordingly, protocols for rapid testing and improved field characterization systems that automatically triangulate electrical resistivity and half-cell corrosion potential measurements would be beneficial allowing discrete / periodic mapping of a structure to be performed as well as addressing testing for asphalt covered concrete. Further, it is the low frequency impedance of rebar in concrete that correlates to corrosion state but these are normally time consuming vulnerable to noise. Hence, it would be beneficial to provide a means of making low frequency electrical resistivity measurements rapidly. Further, prior art techniques for electrical rebar measurements require electrical connection be made to the rebar which increases measurement complexity/disruption / repair / cost even when no corrosion is identified. Beneficially a method of determining the state of a rebar without electrical contact is taught.

In a stress measurement method, an object to be measured is vibrated at a plurality of oscillation frequencies, and a temperature amplitude of the object to be measured is measured by using a temperature sensor. Parameters of a one-dimensional heat conduction equation described below are identified by performing curve-fitting, on the basis of the one-dimensional heat conduction equation, on a measurement value of the temperature amplitude with respect to frequency characteristics of a temperature change component and a phase component based on a thermoelastic effect. The frequency characteristics are obtained at the plurality of oscillation frequencies. The one-dimensional heat conduction equation indicates a theoretical solution of a temperature amplitude on a surface of a coating film based on heat conduction and the thermoelastic effect of each of a substrate and the coating film. Then, a stress of the object to be measured is obtained based on the identified parameters.

In a stress measurement method, an object to be measured is vibrated at a plurality of oscillation frequencies, and a temperature amplitude of the object to be measured is measured by using a temperature sensor. Parameters of a one-dimensional heat conduction equation described below are identified by performing curve-fitting, on the basis of the one-dimensional heat conduction equation, on a measurement value of the temperature amplitude with respect to frequency characteristics of a temperature change component and a phase component based on a thermoelastic effect. The frequency characteristics are obtained at the plurality of oscillation frequencies. The one-dimensional heat conduction equation indicates a theoretical solution of a temperature amplitude on a surface of a coating film based on heat conduction and the thermoelastic effect of each of a substrate and the coating film. Then, a stress of the object to be measured is obtained based on the identified parameters.