A sensor comprising a support and a flexible structure arranged on the support is provided. The flexible structure comprises a frustum-shaped portion having a wider end and a narrower end, wherein the wider end of the frustum-shaped portion is arranged proximal to the support, and an elongated portion extending from the narrower end of the frustum-shaped portion, wherein the flexible structure further comprises a stretchable conducting film arranged on the frustum-shaped portion. A method of preparing such a sensor is also provided.

A sea-floor tethered float instrument containing an accelerometer for measuring wave induced water velocity, ocean currents, relative swell kinetics and the like.

A sea-floor tethered float instrument containing an accelerometer for measuring wave induced water velocity, ocean currents, relative swell kinetics and the like.

A device (10) for determining a parameter of a fluid flow includes an elastically deformable boom (23, 28, 33, 42, 47), with an inflow area (29, 31, 32, 37, 38, 39, 40, 44, 45, 46, 49, 50) for fluid and a measurement apparatus (16) measuring deformation of the boom. A section of the inflow area is aligned askew and/or curved to a main fluid inflow direction (25). The boom has an inflow structure (24, 30, 34, 43, 48) on one free end. The inflow structure has the fluid inflow area. To determine the parameter of the fluid flow at high resolution, in particular a high angle resolution, the boom has a reflection surface (27) on a side facing away from the inflow structure and the measurement apparatus (16) has a laser (17). A beam axis (26) of the laser (17) is directed to the reflection surface (27) of the boom.

A device (10) for determining a parameter of a fluid flow includes an elastically deformable boom (23, 28, 33, 42, 47), with an inflow area (29, 31, 32, 37, 38, 39, 40, 44, 45, 46, 49, 50) for fluid and a measurement apparatus (16) measuring deformation of the boom. A section of the inflow area is aligned askew and/or curved to a main fluid inflow direction (25). The boom has an inflow structure (24, 30, 34, 43, 48) on one free end. The inflow structure has the fluid inflow area. To determine the parameter of the fluid flow at high resolution, in particular a high angle resolution, the boom has a reflection surface (27) on a side facing away from the inflow structure and the measurement apparatus (16) has a laser (17). A beam axis (26) of the laser (17) is directed to the reflection surface (27) of the boom.

Disclosed is inter alia an apparatus (63) for sensing a movement of an object (10, 11) relative to a fluid (12, 13), e.g. for sensing relative movements of a surf board in water. A particular characteristic of the invention is that the housing (21) is mounted in fixed arrangement to a surface (20) of the object, the housing receiving a spring member (62) having a plurality of blades (25a, 25b, 25c, 25d), wherein each blade has an outer end (27) which is fixed to the housing, and an inner end (28) which is connecting to a center portion (65) of the spring, the plurality of blades defining a plane (73), wherein a plurality of strain gauges (26a, 26b, 26c, 26d) is positioned on the blades, and wherein a rigid pin (17) is mounted on the center portion of the spring member which is extending in a direction of a normal vector (74) of the plane and which is protruding from the surface (20) of the object and configured to dip into the fluid.

A sensor for measuring movement of an object relative to a fluid has a housing fixed to a surface of the object and a spring on the housing formed by a plurality of blades each having an outer end fixed to the housing and an inner end connecting to a hub, with the plurality of blades defining a plane. Respective strain gauges are carried on the blades. A rigid pin is mounted on the hub of the spring, extends in a direction generally perpendicular to the plane, and projects from the surface of the object and into the fluid.

An electronic device for detecting an air flow includes at least one sensor having a pair of platelets, each platelet having an RTD and having one end fixed, the other end being free and overlapping the free end of the other platelet. A platelet is flexible so as to form a switch for an electrical circuit. An air flow with a speed higher than a predetermined speed makes the sensor go from a first state, corresponding to a closed switch, in which the free ends of the platelets are in contact, to a second state, corresponding to an open switch, in which said contact is broken. A detection module allows, for each sensor, a resistance of the electrical circuit to be measured, the resistance corresponding to the RTDs being connected in parallel when the switch is closed or to one of the RTDs when the switch is open.

Systems and methods for use in determining a device's speed. The system uses a plate having a front side that is perpendicular to the device's direction of travel. The airflow caused by the device's motion causes the plate to deflect from a resting position and the amount of deflection of the plate is proportional to the speed of the device. The amount of deflection is measured by a rotary encoder coupled to the plate. By properly calibrating the system, the system can determine the device's velocity simply from the airflow caused by the device's motion.

An apparatus including at least one deflecting element and at least one strain sensor is configured for determining relative velocity, fluid flow, or angle of attack between a fluid and a body having a fluid-contacting surface and an opposing non-fluid-contacting surface. The deflecting element is joined to the body and extends from the fluid-contacting surface into the fluid, while the strain sensor is coupled to the non-fluid-contacting surface and is configured to detect strain imparted on the body by deflection of the at least one deflecting element. An output signal of the at least one strain sensor permits calculation of at least one of relative velocity, fluid flow, or angle of attack between the fluid and the body. By measuring deflection of a surface of the body, the at least one strain sensor may be mounted on or along the non-fluid-contacting surface where the environment is controllable, such that the sensor is not subject to deleterious environmental effects.