Performance evaluation methods for microgrippers

In precise manipulation and assembly of components with sub-millimetric dimensions, the role of the gripping tools is fundamental. In the literature, many different types of the socalled microgrippers have been presented, based on different working principles, to cope with the issues related to the gripping, the handling and the release of different microcomponents. Depending on the component properties, the task requirements and the system constraints, a microgripper could be more suitable than another and allow the achievement of higher performance. However, the performance assessment of the microgrippers lacks of a standardized and quantitative methodology. Many authors declare the good capabilities of their tools in a qualitative way or according to the results obtained executing specific and different tasks. For this reason, it is often difficult to compare different microgrippers and estimate the actual results that can be obtained e.g. in the gripping or the release of a component. In this context, after a preliminary survey of the adopted approaches in literature and of their meaning, this paper investigates the conception and formalization of methods and procedures to evaluate the performance of a generic microgripper and the definition of standard performance indices to support the presentation of the microgripper characteristics.