A Microfabricated Planar Digital Microrobot for Precise Positioning Based on Bistable Modules

Abstract

Size reduction is a constant objective in new technologies, for which very accurate devices are needed when manipulating sub-millimetric objects. A new kind of microfabricated microrobot based on the use of bistable modules is designed to perform open-loop controlled micropositioning tasks. The DiMiBot (Digital MicroroBot) opens a new paradigm in the design of microrobots by using mechanical stability instead of complex control strategies. We propose a new architecture of digital microrobot for which forward and inverse kinematics models are easy to use. These kinematic models are validated with FEA simulations before the fabrication of a real DiMiBot prototype. Tests and characterization of the prototype are made and compared to the desired behavior. Thanks to its submicrometric resolution and to its small dimensions (∼ 400 µm thickness), it is able to manipulate micro-objects in confined environments, where no other robot can be used.

Analytical Study of the Snap-Through and Bistability of Beams With Arbitrarily Initial Shape

“…Introducing the different coefficients and constants, the snap-through solution (18) and snapping force expressions ((24), (25), (34)) are obtained. Afterwards, the different snapping points ((29), (32), (33), (38), (39)) and the conditions for reaching different levels of axial compression (28) and for bistability (41) are determined. These steps are summarized in Table 1.…”

“…Bistable beams exhibit additional advantages, such as their simplicity, passive holding, low actuation energy, small footprint, large stroke with small restoring forces, and negative stiffness zone. These advantages make bistable beams suitable for an increasing number of applications at different scales, such as space applications [1], biomedical [2], energy harvesting [3,4], resonators [5], actuators [6] accelerometers [7], shock sensors [8], gas sensors [9], pressure sensors [10], flow sensors [11], grippers [12], mechanisms with large displacement and small actuation stroke [13], switches [14], relays [15], memory devices [16], logics [17], lamina emergent frustrum [18], statically-balanced mechanisms [19], soft robotics [20], constant force mechanisms [21,22], bistable positioning [23][24][25][26], and multistable devices [27][28][29][30][31][32].…”

Trajectory Planning for Micromanipulation With a Nonredundant Digital Microrobot: Shortest Path Algorithm Optimization With a Hypercube Graph Representation

“…Our previous papers have presented the paradigm of digital robotics applied to microscale usage. [16,17] were dedicated to the design and fabrication of the binary actuator (the bistable module), which was used in the first digital microrobot presented in [18,19], named the DiMiBot.…”

Design optimization of bistable modules electrothermally actuated for digital microrobotics

“…With the goal to perform micromanipulation tasks in confined environments, a new approach in the design of microrobots was developed in [3], named "Digital Microrobotics". Its particularity consists in the generation of highly accurate displacements without any sensor.…”

“…The DiMiBot's kinematics with 4 bistable modules named bl 0 , bl 1 , br 0 and br 1 (left), and the microfabricated robot from[3] (right).…”