Ha! I have not had chance yet to view the whole of this video, but I will try to do so.
I just read the last patent in the list provided by
@damirski and his comments on piezoelectric mechanisms, and it has some extremely interesting innovations disclosed in it. I think this patent has given me a whole new level of insight into the comments and terms used in AP's recent announcements, especially concerning the "contact points". This patent reflects a whole new series of steps on the road AP has taken with its MEMS construction and how it is operated. Some of what is said there is pretty amazing tech, and will undoubtedly lead to some
very interesting devices -
including non-audio applications!
Based on a read through the patent text the contact points discussed in the recent announcements are probably not the electrical contacts going
to the MEMS device, as I first assumed, but the contact points / motion limits of the membrane and its flexures with its enclosing body. I suspect this patent reflects the novel innovations disclosed in recent announcements. And these are then reflected in the modifications subsequently announced. I would be unwise to second guess what AP has done or developed from their experimentation, but I think it is likely to lead to some pretty innovative developments to come.
Suffice it to say that I now think it is more likely that they are implementing some of these innovations rather than fixing faults or problems. Just a guess on my part, but I am more encouraged now than I was!
Below are a couple of abstracted comments from the patent. As I understand what I read these define the ability to
angle the membranes and provide steerable sound, and sound with better definition. (amongst other interesting capabilities!!!)
-----
[0060] As discussed below, the straining of the one or more piezoelectric members 130 by the electrical field (or fields) applied thereto may be done in a controllable fashion, for producing a planned movement of moving element 110.
For example, straining all of flexures 120(1), 120(2) and 120(3) to a similar degree would result in movement of moving element 110 perpendicularly to a plane of mechanical support 190, while a plane of moving element 110 remains parallel to that plane. Continuing the same example, straining flexures 120(1), 120(2) and 120(3) in different degrees and/or direction may be used for twisting moving element 110 between planes which are not parallel with respect to the plane of the mechanical support.
[0061] Microelectromechanical apparatus 100 also includes at least one electrode 140 that is connected to at least one of the piezoelectric members 130. It is noted that a single electrode 140 may be connected to a single piezoelectric member 130 (as illustrated) or to more than one of the piezoelectric members 130. Also--two or more electrodes 140 may be connected to any single piezoelectric member 130 (e.g. for transferring of current via the piezoelectric member 130, thereby applying an electric field onto the respective piezoelectric member 130).
[0062] Each of the one or more electrodes 140 is operable to transfer to the at least one piezoelectric member 130 a sequences of electric fields, thereby controllably inducing movement of the moving element 110 for creating the physical effect. It is noted that the one or more electrodes may be connected to a power source and/or to a controller, from which electric voltages may be applied to the electrodes for generating the electric fields straining the one or more piezoelectric members 130.
[0063] FIG. 2 is a side view diagram illustrating an example of microelectromechanical apparatus 100, in accordance with the presently disclosed subject matter. The one or more flexures 120 by which moving element 110 is connected to the mechanical support 190 may define an axis (denoted 101 in FIG. 2) along which the moving element 120 can travel. The structure of the flexures 120 and/or the control scheme according to which electric fields are applied to piezoelectric materials in micro-electromechanical apparatus 100 may be implemented in order to prevent motion of moving element 120 in other directions (i.e. other than along the axis), i.e. moving element 110 may be operative to be constrained to travel alternately back and forth along an axis. It is noted that the same factors (structural and control related) may also define an at-rest position of the moving element 120 (e.g. in the same plane as that of mechanical support 190).
Microelectromechanical apparatus 110 also includes one or more motion restriction mechanisms for maintaining a maximal motion distance for each of the moving elements when being actuated via the corresponding flexure and piezoelectric member.
[0064]
For example, microelectromechanical apparatus 110 may include, as the motion restriction mechanism, one or more mechanical stops 160. More generally, the motion restricting mechanism may include an array of mechanical stoppers 160 associated with the respective array of moving elements, such that each of a plurality of the moving elements is operative to be constrained to travel alternately back and forth along a respective axis, and is held against the mechanical stopper 160 when the electric field applied to the respective piezoelectric member 130 connected to the respective moving element 110 exceeds a threshold value.
[0065] Such a mechanical stop 160 puts a limit to the motion of moving element 110 along the axis 101. When the electric field applied to at least one of the piezoelectric members 130 connected to the moving element 110 exceeds a threshold value, moving element 110 is held against the mechanical stop 160. It is noted that mechanical stops 160 may be implemented to limit the movement of moving element 110 at both ends of the movement along the axis (e.g. as exemplified in FIG. 3), or only at one of them (as illustrated for reasons of simplicity only in FIG. 5).
The mechanical stop 160 may also be constructed such that the moving element 110 will stop in a position that is not parallel to the device surface. [0060] As discussed below, the straining of the one or more piezoelectric members 130 by the electrical field (or fields) applied thereto may be done in a controllable fashion, for producing a planned movement of moving element 110. For example, straining all of flexures 120(1), 120(2) and 120(3) to a similar degree would result in movement of moving element 110 perpendicularly to a plane of mechanical support 190, while a plane of moving element 110 remains parallel to that plane. Continuing the same example, straining flexures 120(1), 120(2) and 120(3) in different degrees and/or direction may be used for twisting moving element 110 between planes which are not parallel with respect to the plane of the mechanical support.
(20min delay)