Most micro-devices use direct actuation technique to drive an actuating element into a given state. Examples include electrostatic, piezoelectric, thermal, and electromagnetic actuation. The most common application of micro-actuators is in micro-switches, where a switching element armature is moved to make an electrical contact between two or more electrical conductors. Oscillating actuation to drive the actuator into a given latched state is not common.
Microactuators are typically directly driven by a control line wire that provides the actuation energy electricity. The use of direct wiring to “address” a device, i.e., to actuate one device and not others, requires each device to have its own actuating wiring or the use of additional electronics to interpret an addressing signal and drive each actuator. This requires multiple wires to be routed to drive multiple actuators. The use of one or more wires per actuator causes a problem in managing space when routing electrical traces on a circuit board. As the number of actuators becomes large more than 3 or 4, the routing problem for the actuation lines becomes very difficult.
There are no known systems that use a single address line to actuate multiple devices, and no known systems that use frequency or time varying waveform to selectively drive a single device on a bus of multiple actuators. Accordingly, it would be desirable to have systems and methods that use a single address line to actuate multiple devices using a waveform that is designed to produce a specific response in the actuator. The simplest example of this is using a harmonic driving force corresponding to the resonant frequency of the actuator.