The invention relates to a compliant structure com prising a frame, a shuttle distant from the frame and mounted on a cantilever that is supported by the frame, wherein the cantilever with the shuttle is movable transversely to and out of a plane of the frame, and wherein the structure further comprises one or more flexures that connect the cantilever with the frame.

WO2017086785A1 discloses an ortho-planar spring, com prising a frame and a shuttle that is perpendicularly movable with respect to the frame, wherein flexible members connect the shuttle to the frame, and wherein in an unloaded condition the frame, the flexible members and the shuttle provide the spring with a flat configuration.

US2013/0038175 discloses a compliant structure com prising a frame, a shuttle distant from the frame mounted on a cantilever that is supported by the frame, wherein the canti lever with the shuttle is movable transversely to and out of a plane of the frame, and wherein the structure further compris es one or more flexures that connect the cantilever with the frame, wherein the cantilever has a body at least in part ex tending in a first direction which points to the shuttle, and that the one or more flexures connect to the shuttle and/or to the cantilever in the vicinity of the shuttle, wherein the flexures are oriented in a second direction, which second di rection is generally transversely with respect to the first direction .

According to the invention the flexures are preloaded causing the flexures to buckle so as to provide a selectable stiffness to the cantilever and to provide the cantilever with a preferential position out of the plane of the frame.

The cantilever may be straight, but it may also have another configuration, such as zigzag shape or a tapered shape.

With the structure of the invention the Eigen fre quency of the structure can be remarkably reduced and the me chanical efficiency and the range of motion of the cantilever can be improved. It is also possible that the out of plane stiffness of the cantilever can be fully compensated such that static balancing can be achieved.

Advantageously the manufacturing cost of the struc ture of the invention and be kept low by implementing the structure as a unitary MEMS structure.

Preferably the cantilever of the compliant structure of the invention is piezoelectric. Motion of the cantilever translates then to electric power, which makes possible that the structure of the invention can be used for energy harvest ing. However also other applications are feasible such as use as an oscillator, an accelerometer, a geophone, a microphone, a force sensor.

Beneficially the frame is clamped between a top pack age element and a bottom package element so as to provide the required sturdiness to the construction.

The invention will hereinafter be further elucidated with reference to the drawing of an exemplary embodiment of a structure according to the invention that is not limiting as to the appended claims.

In the drawing:

-figures 1A and IB show a schematic drawing of the structure of the invention in an isometric view without nones sential parts;

-figure 2 shows a top view at the structure of the invention;

-figure 3 shows the structure of the invention in ex ploded view;

-figures 4A and 4B show the structure of the inven tion in an assembled state;

-figure 5A and figure 5B show the structure of the invention wherein the cantilever has a zigzag shape; and

-figure 6 shows the structure of the invention with a variation in the orientation of the flexures.

Whenever in the figures the same reference numerals are applied, these numerals refer to the same parts.

Figure 1A shows the structure 1 of the invention in an unloaded situation, whereas figure IB shows the structure of the invention in an loaded situation.

The structure 1 comprises a frame 2, a shuttle 3 dis- tant from the frame 2 mounted on a cantilever 4 that is sup ported by the frame 2, wherein the cantilever 4 with the shut tle 3 is movable transversely out of a plane of the frame 2, as is depicted in figure 1A and figure IB. The structure 1 further comprises one or more flexures 5 that connect the can tilever 4 with the frame 2, resulting in a degree of freedom out of plane of the frame 2 as depicted by the axis 6 shown in figure IB. One thing and another is also shown in figure 2, wherein the degree of freedom is of course not shown since that is perpendicular to the sheet of the drawing.

As will be understood from figures 1A/1B and 2 the cantilever 4 has a body extending in a first direction away from where the cantilever 4 is supported by the frame 2 and pointing to the shuttle 3. The one or more flexures 5 connect to the shuttle 3 -as may be best seen in figure 2- and/or to the cantilever in the vicinity of the shuttle, wherein the flexures 5 are oriented in a second direction, which second direction is in this embodiment generally at right angles with respect to the first direction of the cantilever body. A gen erally transverse orientation of the second direction with re spect to the first direction that is not exactly at right an gles is however also possible. An example thereof is shown in figure 6.

The flexures 5 are preloaded causing the flexures to buckle and to provide a selectable stiffness to the cantilever 4 and to provide the cantilever 4 with a preferential position out of the plane of the frame 2. Accordingly the cantilever 4 represents a bi-stable system.

The structure of the invention is preferably a uni tary MEMS structure, but it is also possible to construe the structure with 3D printing and laser micro-machining.

For particular applications it is preferable that the cantilever is piezoelectric. This makes the structure particu larly suitable as a micro-energy harvester.

For practical applications it is desirable that the frame 2 is clamped between a top package element 7 and a bot tom package element 8. An exploded view thereof is provided by figure 3, whereas same in assembled state is shown in figure 4A. Figure 4B corresponds with figure 4A without the top pack- age element 7.

Figure 5A provides a first example of the structure of the invention wherein the cantilever 4 has a zigzag shape, as opposed to the straight configuration of the cantilever 4 as depicted in figures 1 - 4. Also in this embodiment the shuttle 3 is mounted on a cantilever 4 distant from the frame 2, wherein the cantilever 4 is supported by the frame 2. The cantilever 4 with the shuttle 3 is movable transversely to and out of a plane of the frame 2, and the structure 1 further comprises one or more flexures 5 that connect the cantilever 4 with the frame 2. The cantilever 4 has a zig-zag shaped body which at least in part extends eventually in a first direction which points to the shuttle 3. The flexures 5 connect to the shuttle 3, but could also connect to the cantilever 4 in the vicinity of the shuttle 3. Again the flexures 5 are oriented in a second direction that is generally transversely with re spect to the first direction, which points to the shuttle 3.

Figure 5B shows a second example of the structure of the invention wherein the cantilever 4 has a zigzag shape body which at least in part eventually extends in a first direction which points to the shuttle 3. In this second example there is a zigzag shaped 'double' cantilever which is mirrored on oppo site sides of the flexures 5. Also in this example the flex ures 5 are oriented in a second direction that is generally transversely with respect to the first direction of the 'dou ble' cantilever 4, which points to the shuttle 3.

Figure 6 depicts the situation that the structure of the invention is embodied with flexures 5 that are not exactly at right angles but that are oriented in a second direction, which second direction is generally transversely with respect to the first direction in which the cantilever 4, which in this case is tapered, extends from the point where the canti lever 4 connects to the frame 2.

Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the structure of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the append- ed claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment.