Micromechanical devices often include piezoelectric material, which undergoes a dimensional change upon application of a sufficient bias across the material. Although such piezoelectric material devices may work relatively well for some uses, such devices are problematic with regard to several applications. In particular, use of micromechanical structures that include piezoelectric material to effect a dimensional change typically requires application of a relatively large bias to cause a relatively small dimensional change in the material, and any dimensional change relaxes once the bias is removed. Thus, the devices require continuous application of a relatively large bias for so long as the material change is desired.
Additional problems arise because devices including typical piezoelectric materials are difficult to integrate with integrated circuits and microelectomechanical systems (MEMS). Consequently devices using piezoelectric materials are often reserved for discrete as opposed to integrated devices.
Other forms of piezoelectric material structures can be formed in such a way that a continuous bias is not required to sustain a dimensional change. However, these structures are relatively difficult to manufacture and are difficult to integrate with other devices.
Accordingly, improved micromechanical structures and devices including the structures that are relatively easy to fabricate, that are relatively easy to integrate with other devices, and that are relatively non-volatile are desired.