Micro/macro force-servoed gripper for precision photonics assembly and analysis

Abstract

Link to this article: http://journals.cambridge.org/abstract_S0263574704000839How to cite this article: Richard M. Voyles and Seth Hulst (2005). Micro/macro force-servoed gripper for precision photonics assembly and analysis. SUMMARYPhotonics is a field that straddles both the macro and micro worlds. It largely deals with macro-scale devices, but many of these require sub-micron-scale precision in assembly. This makes it a very interesting application domain. We describe a microgripper for microassembly of photonic devices and micro-exploration of the properties of sub-micron attachment means (such as solder and UV epoxy). The microgripper has multi-degree-of-freedom actuation and a unique micro/macro actuator on the gripping axis to facilitate human loading and unloading and also very precise accommodation. We demonstrate the force sensitivity and stiffness of approximately 20 mN and 70 mN/um, respectively to be sufficient for the intended tasks. Finally, we demonstrate the gripper accommodating forces of a large solder ball freezing and cooling as a prelude to our intended study of sub-millimeter solder balls in sub-second heating regimes.

Micron: An Actively Stabilized Handheld Tool for Microsurgery

“…Though such feats of dexterity are remarkable, it seems likely that some technical means for stabilizing hand motion during microsurgery would allow more consistent outcomes for existing procedures, and (more importantly) allow the development of new procedures currently made impractical by the accuracy limits of unaided manipulation [4, 5]. We have concentrated on applications to eye surgery due to the high accuracy required, but such technologies would likely be valuable in other areas of surgery [6] and for other applications such as biological research [7] or industrial assembly tasks [8]. Before discussing the state of the art we must review relevant properties of the human component in an aided manipulation system: tremor characteristics, and human-in-the-loop dynamics.…”

Grasping and Interaction Force Feedback in Microassembly

“…The grasping force is usually detected by two fingers mechanical micro-grippers equipped with sensors [4], [5], [6], [7], [8], [9], [10]. Some of these grippers are also able to sense interaction force, along one degree of freedom (DOF), perpendicular [4], [5] or parallel [6] to the grasping plane (i.e. the plane defined by the opening and closing of the fingers of the gripper).…”

“…Usually, there is a trade-off between stroke and force resolution and between maximum force and force resolution. This trade off is evident in the two main types of micro-grippers: siliconbased micro-grippers [5], [6], [9], [10] and hybrid micro-grippers [4], [7], [8]. The silicon micro-grippers usually offer the best resolution while the hybrid ones the best stroke and the maximum grasping force.…”

“…Silicon micro-grippers are directly fabricated with integrated actuators (electrostatic [9] or thermal [6], [10]) and sensors (piezoresistors [5], [10] or capacitive sensors [6], [9]). In hybrid micro-grippers the mechanical structure of the grippers, the actuators (piezo-elements [4], [8], electromagnets [7] or SMA actuators [8]) and sensors (usually strain gauges [4], [8] glued or fixed to the mechanical structure) are produced separately and then assembled together.…”

Recent development in micro-handling systems for micro-manufacturing

“…Henein et al design a gripper composed of an original three-dimensional compliant mechanism based on flexible bearings, an inchworm piezoelectric actuator, and exchangeable gripping jaws [30]. Voyles and Hulst design a compact, active, multi-degree-of-freedom, force-servoed gripper [31]. Thompson and Fearing introduced an alternative micro-assembly system based on two 1-DOF probes that are orthogonal to each other and a 3-DOF translating stage [32].…”