High Bandwidth Microgripper With Integrated Force Sensors and Position Estimation for the Grasp of Multistiffness Microcomponents

Abstract

At the microscale, small inertia and high dynamics of microparts increase the complexity of grasping, releasing and positioning tasks. The difficulty increases especially because the position, the dimensions and the stiffness of the micropart are unknown. In this paper, the use of a microgripper with integrated sensorized end-effectors with high dynamic capabilities is proposed to perform stable and accurate grasps of multistiffness microcomponents. A dynamic nonlinear force/position model of the complete microgripper while manipulating a microcomponent is developed. The model takes into consideration not only free motion and constrained motion, but also, contact transitions which is a key issue at the microscale due to the predominance of surface forces. It enables to estimate the position of the microgripper's end-effectors, the contact position of the microcomponent and the force applied on the microcomponent. Using the proposed microgripper and its model, both of the gripping forces are measured and the position of each of the microgripper's endeffectors is estimated. This enables to perform a stable grasp of the micropart by providing force and position feedback. Moreover, using the developed microgripper and its model, the characterization of the microcomponent can be performed by estimating its dimensions and its stiffness.

A Two-Axis Piezoresistive Force Sensing Tool for Microgripping

“…The device performance we are aiming for in this work constitutes a range of few μ N to some mN of the force sensing capability along the two axes, which can be used for instrumented microgripper development. We opted for the piezoresistive sensing principle, as it allows a compatible trade-off in terms of the aimed performances as demonstrated in [ 16 ]. The key phenomenon therefore includes the physical change detection (external force) in terms of resistance change and mapping the detected change in terms of force change.…”

“…In the context of micromanipulation, a direct force sensing mechanism [ 16 ] can bring more reliant information than curvature sensing alone. Depending on the requirements, several microgrippers integrating force sensing capabilities have been developed in these recent years, such as [ 17 , 18 ].…”

Analysis of Forces during UV Glue Curing for Micro-Assembly Applications

“…Step: 4 kg > k f (4) and force sensor stiffness. One important point of interest in the current analysis is the varying stiffness of the glue, which means k g is not constant, and the respective variation range of the glue stiffness need to be considered.…”

“…Even with the availability of several micro-fabrication technologies, the robotized approach for precise micro-assembly is still a big need. In the recent years, there were several development in micro-assembly works, in context of different approaches such as using Laser die transfer technique [1], with microfluidic interconnection [2], and with Laser scanning confocal image alignment [3], whereas different strategies to handle complex task [4] and highly accurate assembly tasks [5]- [7] have also been demonstrated. For micro-assembly applications including MEMS devices, use of the glue is one of the widely used techniques in industries.…”

Development and Hybrid Position/Force Control of a Dual-Drive Macro-Fiber-Composite Microgripper

“…However, a single MFC manipulator was investigated, and only the position control was conducted. Generally, the synchronous control of the gripper position and the gripping force is extremely challenging, but is essential in precision micromanipulation tasks [14]. In [15,16], a switching control scheme was proposed to regulate the position and force of the piezoelectric microgripper in an alternate manner.…”