Externally resonated linear microvibromotor for microassembly

A new method for on-substrate fine positioning of microscale/mesoscale disc rete components is presented [1]-[3], where component positions are finely adjusted using microlinear sliders and fixtures on the substrate. Each micr olinear slider is actuated by vibratory impacts exerted by two pairs of mic rocantilever impacters. These microcantilever impacters are selectively res onated by shaking the entire substrate with a piezoelectric vibrator, requi ring no need for built-in driving mechanisms such as electrostatic comb act uators, as reported previously [4], [5]. This selective resonance of the mi crocantilever impacters via an external vibration energy field [6] provides with a very simple means of controlling forward and backward motion of the microlinear slider, facilitating assembly and disassembly of a microcompon ent on a substrate. An analytical model of the device is derived in order t o obtain, through the simulated annealing algorithm, an optimal design, whi ch maximizes translation speed of the linear slider at desired external inp ut frequencies. Prototypes of the externally resonated linear microvibromot or are fabricated using the three-layer polysilicon surface micromachining process provided by the Microelectronics Center of North Carolina, Research Triangle Park, NC, multiuser microelectromechanical processes service, The se prototypes are tested for forward and backward motion via external vibra tion applied by an piezoelectric flexure vibrator, as well as the horizonta l positioning and release of 500-mu m-square polysilicon chips against a re ference fixture element anchored to the substrate.