Abstract:
A gyroscope structure with a specific arrangement of drive and sense structures and coupling spring structures, which allows orthogonally directed motions of larger scale drive and sense structures in a very limited surface area.

Description:
BACKGROUND 
     Field 
     The present invention relates to microelectromechanical devices and to a gyroscope structure and a gyroscope. 
     Description of the Related Art 
     Micro-Electro-Mechanical Systems, or MEMS, can be defined as miniaturized mechanical and electro-mechanical systems where at least some elements have a mechanical functionality. Since MEMS devices are created with the same tools used to create integrated circuits, micromachines and microelectronics can be fabricated on the same piece of silicon or other substrate to enable advanced machines. 
     MEMS structures can be applied to quickly and accurately detect very small changes in physical properties. For example, a microelectromechanical gyroscope can be applied to quickly and accurately detect very small angular displacements. Motion has six degrees of freedom: translations in three orthogonal directions and rotations around three orthogonal axes. The latter three may be measured by an angular rate sensor, also known as a gyroscope. MEMS gyroscopes use the Coriolis Effect to measure the angular rate. When a mass is moving in one direction and rotational angular velocity is applied, the mass experiences a force in orthogonal direction as a result of the Coriolis force. The resulting physical displacement caused by the Coriolis force may then be read from, for example, a capacitive, piezoelectrical or piezoresistive sensing structure. 
     In MEMS gyros the primary motion cannot be continuous rotation as in conventional ones due to lack of adequate bearings. Instead, mechanical oscillation may be used as the primary motion. When an oscillating gyroscope is subjected to an angular motion orthogonal to the direction of the primary motion, an undulating Coriolis force results. This creates a secondary oscillation orthogonal to the primary motion and to the axis of the angular motion, and at the frequency of the primary oscillation. The amplitude of this coupled oscillation can be used as the measure of the angular rate. 
     Gyroscopes are very complex inertial MEMS sensors, and still the tendency is towards more and more compact structures. The basic challenge in gyroscope designs is that the Coriolis force is very small and therefore the generated signals tend to be minuscule compared to other electrical signals present in the gyroscope. Spurious responses and susceptibility to vibration plague many compact MEMS gyro designs, like conventional tuning fork structures. 
     One known approach to reduce sensitivity to external vibrations is a balanced ring structure that includes a planar vibratory resonator that has a ring or hoop like structure with inner or outer peripheries extending around a common axis. The planar resonators are typically excited into a cos 2θ resonance mode that exists as a degenerate pair of vibration modes at a mutual angle of 45°. One of these modes is excited as the carrier mode. When the structure is rotated around the axis normal to the plane of the ring, Coriolis forces couple energy into a response mode. The amplitude of motion of the response mode gives a direct measure of the applied rotation rate. 
     A disadvantage of the ring structure is that the sectional seismic masses and their displacements are relatively small, resulting to low signal levels. Also the dimensions of the sectional actuation and sensing structures make the functions indistinguishable and thus compromised. 
     SUMMARY 
     An object of the present invention is to provide a compact gyroscope structure that is insensitive to external shocks. The objects of the present invention are achieved with a gyroscope structure according to the characterizing portions of the independent claims. 
     In certain embodiments, a microelectromechanical gyroscope structure includes a first pair of drive structures having a first drive structure and a second drive structure. The first drive structure is coupled to a first seismic mass and the second drive structure is coupled to a second seismic mass. A second pair of drive structures includes a third drive structure and a fourth drive structure, and the third drive structure is coupled to a third seismic mass and the fourth drive structure is coupled to a fourth seismic mass. Each drive structure includes a transducer configured to induce primary oscillation of the corresponding seismic mass. A first pair of sense structures includes a first sense structure and a second sense structure, and a second pair of sense structures comprising a third sense structure and a fourth sense structure. The seismic masses of at least one pair of the first and second drive structures are coupled to oscillate in opposite phase and are aligned to a common axis of primary oscillation. An axis of primary oscillation of the first pair of drive structures and an axis of primary oscillation of the second pair of drive structures extend orthogonally along a plane of oscillation. Each sense structure includes a sense device and a coupling spring structure; the coupling spring structure connects the sense device to at least one seismic mass of the first pair of drive structures and to at least one seismic mass of the second pair of drive structures. The coupling structure is configured to relay to the sense device a component of the motion of each of the seismic masses in a direction perpendicular to their axis of primary oscillation, and to absorb a component of the motion of each of the seismic masses in a direction of their axis of primary oscillation. The sense device is suspended to a static support and configured to oscillate in a direction diagonal to the axis of primary oscillation of the first pair of drive structures and diagonal to the axis of primary oscillation of the second pair of drive structures. 
     Embodiments of the invention can also include a gyroscope that includes the microelectromechanical gyroscope structure. Various embodiments of the invention are disclosed in the specification and recited in the dependent claims. 
     Embodiments of the present invention are based on an arrangement of drive and sense structures and coupling spring structures, which allows orthogonally directed motions of larger scale drive and sense structures in a very limited surface area. 
     Further advantages of the invention are discussed in more detail with the following embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following the invention will be described in greater detail, in connection with preferred embodiments, with reference to the attached drawings, in which 
         FIG. 1  illustrates an embodiment of a gyroscope structure; 
         FIG. 2  illustrates an exemplary drive structure; 
         FIG. 3  shows an exemplary central spring structure; 
         FIG. 4  illustrates drive mode motion of the gyroscope structure; 
         FIG. 5  illustrates an exemplary sense structure; 
         FIG. 6  illustrates sense mode motion of the gyroscope structure; 
         FIG. 7  illustrates another exemplary sense structure; and 
         FIG. 8  illustrates elements of a gyroscope. 
     
    
    
     DETAILED DESCRIPTION 
     The following embodiments are exemplary. Although the specification may refer to “an”, “one”, or “some” embodiment(s), this does not necessarily mean that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may be combined to provide further embodiments. 
     In the following, features of the invention will be described with a simple example of a device architecture in which various embodiments of the invention may be implemented. Only elements relevant for illustrating the embodiments are described in detail. Various implementations of gyroscope structures that are generally known to a person skilled in the art may not be specifically described herein. 
       FIG. 1  illustrates an embodiment of a gyroscope structure according to an embodiment of the present invention. The shown structure includes four seismic masses  100 ,  102 ,  104 ,  106 , drive structures  120 ,  122 ,  124 ,  126 , and sense structures  170 ,  172 ,  174 ,  176 . Two drive structures  120 ,  122  form a first pair of drive structures, and other two drive structures  124 ,  126  form a second pair of drive structures.  FIG. 2  illustrates in more detail an exemplary drive structure  120  of  FIG. 1 . 
     A drive structure  200  refers here to a combination of elements that suspend a seismic mass  202  and induce it to a drive mode primary oscillation. The term seismic mass refers here to a mass body that may be suspended to a static support to provide an inertial movement. The seismic mass  202  may have a planar form. This means that at least part of the volume of the seismic mass extends along a plane in two dimensions (length, width) and forms therein a planar surface. Within tolerances, the planar surface of the seismic mass can be considered to contain straight lines that connect any two points on it. It is, however, understood that the surface may include protrusions patterned on the seismic mass, or recesses patterned into the seismic mass. 
     For the primary oscillation, the drive structure  200  may suspend the seismic mass  202  to another body element of the gyroscope by means of a first spring structure  206 ,  220  that allows the seismic mass  202  two degrees of freedom in a plane of oscillation. The first spring structure may include a primary element  206  for the first degree of freedom and a secondary element  220  for the second degree of freedom. The primary element  206  may include an anchor element  208  and a suspension spring  210 . The anchor element  208  may provide a connection to a static (non-oscillating) support, typically to another body element. If the gyroscope structure is a MEMS structure wafer, the other body element may be provided, for example, by an underlying handle wafer, or a covering cap wafer of a gyroscope die. The suspension spring  210  may extend between the seismic mass  202  and the anchor element  208  in a directional manner such that the suspension spring  210  is very elastic in one direction and rigid in another direction that is perpendicular to it. This means that the force that the suspension spring  210  exerts against its displacement in one direction is multifold to the force the suspension spring  210  exerts against its displacement in a direction perpendicular to it. The direction in which the suspension spring  210 , and thereby the primary element  206  is elastic may correspond to the first degree of freedom, i.e. the direction of primary oscillation of the seismic mass  202 . Primary oscillation refers here to directional reciprocating motion, which results from excitation of the seismic mass  202 . 
     The secondary element  220  may be arranged between the seismic mass  202  and the primary element  206  in a directional manner and orthogonally such that the direction in which the secondary element is elastic may correspond to the second degree of freedom, i.e. the direction of secondary oscillation of the seismic mass  202 . Secondary oscillation refers here to directional reciprocating motion, which results from Coriolis force resulting from angular motion induced to the gyroscope structure. The secondary element may include a bending beam positioned such that its longitudinal dimension is initially in the direction of the primary oscillation of the seismic mass  202  and couples directly or indirectly a lateral point in the seismic mass  202  and a lateral point of the primary element  206 .  FIG. 2  illustrates indirect coupling that includes a rigid oblique extension that offsets the coupled points in the plane of oscillation. Other spring structures for arranging directional oscillation may be applied within the scope. As a result of combining the primary element  206  and the secondary element  220 , the seismic mass  202  has a degree of freedom in the direction of primary oscillation and in the direction of secondary oscillation. 
     The drive structure  200  may comprise also a transducer  204  that transforms input electrical energy into mechanical energy of the seismic mass. The exemplary drive structure of  FIG. 2  applies electrostatic actuation with a comb drive where the capacitances between stator comb  212  and rotor comb  214  pairs changes linearly with displacement of the rotor comb. Other forms of capacitive actuation may be applied within the scope. For example, parallel plate combs or hybrid combs that combine features of parallel plate and longitudinal capacitors may be used. Also piezoelectrical excitation may be applied. Corresponding excitation methods are well known to a person skilled in the art, and will not be discussed in more detail herein. 
     Returning to  FIG. 1 , in the first pair of drive structures  120 ,  122 , and the second pair of drive structures  124 ,  126 , the seismic masses are coupled for antiphase primary oscillation in a direction of a common axis of primary oscillation  128 ,  130 , respectively. An axis of primary oscillation refers here to an axis that is aligned with the direction of the primary oscillation, and coincides with the seismic mass. Advantageously the seismic mass has an axis of symmetry and the axis of primary oscillation coincides with the axis of symmetry of the seismic mass. Primary oscillation of two seismic masses  100 ,  102  or  104 ,  106  coupled to the pair of drive structures  120 ,  122  or  124 ,  126  is configured to take place in a direction of a common axis of primary oscillation  128  or  130 , respectively. 
     The configuration of  FIG. 1  is shown associated to directions X and Y, which will herein be referred to as horizontal and vertical directions. One drive structure of the first pair of the drive structures may be called a first vertical drive structure  120  and the opposite drive structure of the first pair of the drive structures a second vertical drive structure  122 . Correspondingly, the second pair of drive structures may include a first horizontal drive structure  124  and a second horizontal drive structure  126 . In primary motion, the seismic mass in each of the vertical drive structures  120 ,  122  oscillates reciprocally in a direction of a vertical axis  128  of primary oscillation. Correspondingly, the seismic mass of each of the horizontal drive structures  124 ,  126  oscillates reciprocally in a direction of a horizontal axis  130  of primary oscillation. 
     The primary oscillation of the seismic masses in a pair of drive structures is anti-phase motion. This means, for example, that the oscillation of the seismic mass of the first vertical drive structure  120  has the same frequency and is referenced to a same point in time as the seismic mass of the second vertical drive structure  122 , but the phase difference between them is 180 degrees (π radians). Accordingly, the seismic masses move with a same rate towards each other or away from each other. Primary oscillation of the seismic masses of the horizontal drive structures is similar, but in the horizontal direction. 
     Direction of the primary oscillation of the seismic mass depends on the geometry of the drive structure. The direction may be further substantiated with a drive coupling spring structure that improves the accuracy of frequency and direction of the anti-phase drive motion.  FIG. 3  shows in more detail an exemplary central spring structure  300  of  FIG. 1  for such drive coupling. The spring structure  300  includes a number of elongate beams that may be considered to rigidly relay motion in a direction of their longitudinal dimension, but flex in a direction perpendicular to their longitudinal dimension. The spring structure may include four diagonal beams  302 ,  304 ,  306 ,  308 . One end of each of the diagonal beams  302 ,  304 ,  306 ,  308  may be anchored to a static support in an anchor point  310 ,  312 ,  314 ,  316  between a seismic mass of a first pair of drive structures and a seismic mass of a second pair of drive structures. The diagonal beams  302 ,  304 ,  306 ,  308  may extend from their respective anchor points inwards, meaning towards a center point  318  within the gyroscope structure where the vertical axis of primary oscillation  128  and the horizontal axis of primary oscillation  130  cross. The other end of the diagonal beams  302 ,  304 ,  306 ,  308  may be connected to two coupling beams that extend from the point of connection through drive structures to neighboring seismic masses. 
     For example, the diagonal beam  302  of  FIG. 3  is supported to the anchor point  310  and extends inwards therefrom. At a connection point  320 , before the center point  318 , the diagonal beam  302  is connected to two coupling beams  322 ,  324 . One end of the first coupling beam  322  is connected to one end of the second coupling beam  324  and to one end of the diagonal beam  302 , and the other end of the first coupling beam  322  is connected to move along the primary oscillation of the first vertical drive structure  120 . The other end of the first coupling beam  322  may be connected to a moving part of the first vertical drive structure  120 , advantageously to a point in its axis of primary oscillation  128 . One end of the second coupling beam  324  is connected to one end of the first coupling beam  322  and to one end of the diagonal beam  302 , and the other end of the second coupling beam  324  is connected to move along the first horizontal drive structure  124 . The other end of the second coupling beam  324  may be connected similarly to a point in the axis of primary oscillation of the first horizontal drive structure  124 . 
     Similar coupling beam pairs may be arranged to connect inward pointing ends of each of the diagonal beams  302 ,  304 ,  306 ,  308 , as shown in  FIG. 3 . Since the connection point  320  of the diagonal beam  302  and its two coupling beams  322 ,  324  is in a position before the center point  318 , the coupling beams  322 ,  324  that connect to a first vertical drive structure  120  form initially a small acute angle with its axis  128  of primary oscillation. The same orientation of coupling beams may repeat for all drive structures. 
       FIG. 4  illustrates operation of the drive structure configurations of  FIG. 1  during primary motion when the structure is in operation. When the first vertical drive structure  120  moves outwards in the direction of the axis  128  in primary motion, the coupling beams  322 ,  326  move along with the primary oscillation, and flex towards the axis  128 . Also the coupled ends of diagonal beams  302 ,  306  flex towards the axis  128  along with the primary oscillation, and the acute angle of the coupling beams  322 ,  326  with the axis  128  of primary oscillation of first vertical drive structure  120  decreases. The corresponding flexing and decrease of the acute angle between the corresponding coupling beams and the axis  128  happens in the opposite side in the second vertical drive structure  122 . However, at the same time the acute angle between the corresponding coupling beams and the axis  130  in the neighboring horizontal drive structures  124 ,  126  increases. 
     On the other hand, when the vertical drive structures  120 ,  122  move inwards (not shown), and the neighboring drive structures  124 ,  126  are in outward motion. The acute angle between the coupling beams  322 ,  326  of the first vertical drive structure  120  increases. The corresponding flexing and decrease of the acute angle between the corresponding coupling beams and the axis  128  happens in the opposite side in the second vertical drive structure  122 . The coupled ends of diagonal beams  302 ,  306  flex away from the axis  128  along with the primary oscillation. The acute angle between the corresponding coupling beams of the horizontal drive structures  124 ,  126  and the axis  130  decreases, and the coupled ends of their diagonal beams flex towards the axis  130 . 
     The described combination of the diagonal beams and the coupling beams forms a drive coupling spring structure that very efficiently forces the primary oscillation of each opposite pair of drive structures to anti-phase mode, and the primary oscillation of the two pairs of drive structures to two orthogonal directions of the common axes  128 ,  130  of primary oscillation. 
     The drive structures may include also further elements for other characteristics provided by the gyroscope structure. For example, the vertical drive structures  120 ,  122  of  FIG. 1  are shown to include further comb structures  160 ,  162  for drive sense signals. Such signals may be applied for controlled force feedback operations within the drive structure. As another example, the horizontal drive structures  124 ,  126  of  FIG. 1  may include further comb structures  164 ,  166  for electrostatic quadrature compensation. 
     A sense structure refers here to an element that is arranged to sense a specific motion of at least one seismic mass, and generate a signal that corresponds with the sensed motion. In a gyroscope structure, the sensed motion results from Coriolis force that is created by angular motion of the gyroscope structure. The gyroscope structure may include a first pair of sense structures  170 ,  172  and a second pair of sense structures  174 ,  176 . 
       FIG. 5  shows in more detail the exemplary sense structure  170  of  FIG. 1 . A sense structure  500  may include a sense device  502 , and a sense coupling spring structure  504 . The sense device  502  may comprise a transducer that transforms input mechanical energy into electric energy. The input mechanical energy results from motion of the one or more seismic masses the sense device is coupled to. The transducer may include a stator  506  and a rotor  508 . The sense device  502  may also include a second spring structure  530  arranged to suspend the rotor to a static support such that it can oscillate in a direction diagonal to the axis  128  of primary oscillation of the vertical pair of drive structures, and diagonal to the axis  130  of the horizontal pair of drive structures. A diagonal direction in this context means that the direction forms a 45° (π/4) angle with the axis. In the structure of  FIG. 1 , it may be seen that the second spring structure  530  is very elastic in the diagonal direction and very rigid in directions other than the diagonal direction. 
     The sense coupling spring structure  504  may couple the rotor  508  to two seismic masses, a seismic mass  100  of a neighboring drive structure  120  of the vertical pair of drive structures, and a seismic mass  106  of a neighboring drive structure  126  of the horizontal pair of drive structures. The sense coupling spring structure  504  may be configured to relay to the rotor  508  a component of motion of the seismic mass  100  of the neighboring drive structure  120  of the vertical pair of drive structures in a direction perpendicular to its axis  128  of primary oscillation, and deflect in a direction of its axis  128  of primary oscillation. Correspondingly, sense coupling spring structure  504  may be configured to relay to the rotor  508  a component of motion of the seismic mass  106  of the neighboring drive structure  126  of the horizontal pair of drive structures in a direction perpendicular to its axis  130  of primary oscillation, and deflect in a direction of its axis  130  of primary oscillation. 
     In the exemplary structure of  FIG. 5 , the sense coupling spring structure  504  may include a first sense beam  510  and a second sense beam  512 . The rotor  508  may extend via an extension beam  514  to a coupling point  516 . The first sense beam  510  may extend between the coupling point  516  and the seismic mass  100  of the vertical drive structure  120  and the second sense beam  512  may extend between the coupling point  516  and the seismic mass  106  of the horizontal drive structure  126 . At sensing, the components of motion of the seismic masses  100 ,  106  accumulate and result in linear oscillation in the diagonal direction shown with the arrow of  FIG. 5 . The configuration of elements may be repeated symmetrically in all sense structures  170 ,  172 ,  176 ,  174 , as shown in  FIG. 1 . 
       FIG. 6  illustrates sense mode motion (secondary oscillation) of the described structures of the gyroscope structure. When the primary mode motion takes place as described in  FIG. 4 , angular motion of the gyroscope structure may create a Coriolis force that falls upon the seismic masses of the gyroscope structure in a direction perpendicular to their primary oscillation. As an example, let us assume that the structure of  FIG. 1  is exposed to angular motion in z-direction. At a certain point of time illustrated in  FIG. 6 , the Coriolis force may be considered to displace the seismic mass  100  coupled to the first vertical drive structure  120  to the positive x-direction, the seismic mass  102  of the second vertical drive structure  122  to the negative x-direction, the seismic mass  104  of the first horizontal drive structure  124  to the positive y-direction, and the seismic mass  106  of the second horizontal drive structure  126  to the negative y-direction. 
     The sense coupling spring structure  504  relays these displacements to the coupling point  516  of the first sense structure  170 , and induces the rotor of the first sense structure  170  into linear motion in a direction shown with an arrow. The shown direction is diagonal to the axis  128  of primary oscillation of the first vertical drive structure  120  and to the axis  130  of primary oscillation of the second horizontal drive structure  126 . In the specific point of time of  FIG. 6 , the displacements of the seismic masses  100 ,  106  can be considered to move the rotor of the first sense structure  170  diagonally inwards, towards the center point  318 . At the same time, the displacements of the seismic masses  102 ,  104  may be considered to move a rotor of a second sense structure  172  of the first pair of sense structures similarly diagonally inwards. On the other hand, the displacements of seismic masses  100 ,  104  are relayed to a rotor of a first sense structure  174  of the second pair of sense structures, inducing it to move diagonally outwards, away from the center point  318 . Similarly, seismic masses  102 ,  106  may be considered to move the rotor of a second sense structure  176  of the second pair of sense structures diagonally outwards. 
     When the direction of the displacement of the seismic masses reverses (not shown), the displacements of the seismic masses  100 ,  106  can be considered to move the rotor of the first sense structure  170  diagonally outwards, the displacements of the seismic masses  102 ,  104  to pull the rotor of the second sense structure  172  of the first pair of sense structures diagonally outwards, the displacements of the seismic masses  100 ,  104  to push the rotor of the first sense structure  174  of the second pair of sense structures diagonally inwards, and the displacements of the seismic masses  102 ,  106  to push the rotor of the second sense structure  176  of the second pair of sense structures diagonally inwards. Accordingly, angular motion of the structure induces diagonal cyclic oscillation of rotors of the orthogonally directed sense structures  170 ,  172 ,  174 ,  176 . This oscillation is secondary oscillation that may be converted into an electrical signal that represents the angular motion experienced by the gyroscope structure. 
     Due to the described symmetric and orthogonal arrangement of the seismic masses  100 ,  102 ,  104 ,  106 , drive structures  120 ,  122 ,  124 ,  126 , and sense structures  170 ,  172 ,  174 ,  176 , the total linear momentum and angular momentum of elements moving in the primary oscillation and in the secondary oscillation during a cycle of oscillation is practically zero. This significantly reduces the extent to which the drive mode and the sense mode couple to linear or angular acceleration. In addition, the arrangement of elements results in balanced inertial forces. This reduces leaking of energy to the surroundings, and thereby enables a high quality factor for resonators implemented with the configuration. The balanced inertial forces also provide robustness against external vibration. 
     Furthermore, in the described configuration, the drive mode and sense mode resonance frequencies are the lowest ones. All other modes may be at least two times higher in frequency than the drive mode and the sense mode. In microscale elements, manufacturing tolerances are inevitable. In conventional structures, external shocks or vibrations may therefore cause a common mode motion that tends to couple to the drive or sense motion. These modes occur typically in a frequency that is close to the frequency of the drive motion or the sense mode resonance frequency, and lower than at least either of them. Now that the undesired common mode frequencies are remarkably higher, the mode is also stiffer, and the amplitude of the motion caused by external vibrations is smaller. The configuration of the claimed drive and sense structures provides a strong coupling (i.e. the difference in frequency of common mode and differential mode vibrations is large, of the order of the frequency of the differential mode vibrations), which makes the gyroscope structure exceptionally robust against external vibration. 
     Due to the specific arrangement of drive and sense structures and coupling spring structures, the sense structures do not essentially displace in the drive mode, and the drive structures do not essentially displace in the sense mode. Since the displacement of the sense structures in the drive mode is effectively minimized, common mode error signals from a pair of sense structures are very small. In addition, errors may be further reduced by applying differential measuring principles that, as such, are well known to a person skilled in the art. 
     In microelectromechanical structures there may exist second-order effects, like harmonic signals caused by nonlinear and/or rotational displacements of the moving elements. In the described configuration, the displacements of the drive structures and the sense structures are and remain rectilinear, even with high amplitudes of up to ten micrometers. 
       FIG. 7  illustrates an alternative sense structure applicable in a microelectromechanical gyroscope structure. In this solution, the transition from the mechanical into electrical domain applies piezoelectricity. The sense structure may include a piezoelectric sense device  702 , and a second spring structure  730  arranged to suspend the sense device  702  to a static support such that it can move in a direction diagonal to the axis of primary oscillation of the vertical pair of drive structures, and diagonal to the axis of the horizontal pair of drive structures. 
     As described in  FIG. 5 , the sense coupling spring structure  704  may couple the sense device  702  to two seismic masses relay to the sense device a component of motion of both of the seismic masses. The sense device  702  may extend via an extension structure  714  to a coupling point  716  to connect with the coupling spring structure  704 . At sensing, the components of motion of the seismic masses accumulate and result in linear oscillation in the diagonal direction shown with the arrow of  FIG. 7 . 
     The piezoelectric sense device  702  may include at least one detection element  740 . The detection element may be a detection beam, arranged to deflect according to the motion of the coupling point. The detection beam  740  may be coupled from both of its ends to the mobile extension structure  714  and from its center to an anchor, or anchored structure.  FIG. 7  shows an example, where the sense device includes a first beam  740 , and a second beam  742 . The first beam  740  may be coupled from both of its ends to the mobile extension structure  714 , and from its center to the center of the second beam  742 . The second beam  742  may be anchored to a support structure from each of its ends. By means of this, the coupling beams  740 ,  742  are arranged to deflect according to motion of the coupling point. The detection beams  740 ,  742  may include a piezoelectric film deflecting along the deflection of the detection beam. The resulting charge may be read and used as a signal to represent the sensed motion. 
       FIG. 8  illustrates elements of a gyroscope that includes a first part  800  and a second part  802 . The first part  800  may include the gyroscope structure of  FIG. 1 , and the second part  802  may include an electrical circuit that is connected to exchange electrical signals with the gyroscope structure. As shown in  FIG. 2 , signals s 1  may be input from sense structures to the electrical circuit  802 , or from the electrical circuit to the gyroscope structure. An output signal S corresponding to the detected angular motion may be calculated from the signals s 1 . 
     The gyroscope may be included in a combined sensor element that includes a variety of sensor elements, a wired or mobile computing, gaming or communication device, a measurement device, a rendering device, or a vehicle function control unit, to name a few. 
     It is apparent to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in various ways. The invention and its embodiments are therefore not restricted to the above examples, but they may vary within the scope of the claims.