Study on applicability of adhesive forces for micro-material handling in production technology

Micro-material handling and micro-assembly becomes increasingly important in largevolume manufacturing of products like sensors in automotive applications. Smaller dimensions of the micro-objects lead to problems with regard to the reliability of the manufacturing process because adhesive forces become predominant over gravity for objects whose dimensions are in the micro-range. In contrast to the common approach of minimizing those adhesive forces, this paper focuses on the use of the three main adhesive forces, van-der-Waals, electrostatic and surface tension forces, as gripping principles. These forces are compared to conventional vacuum grippers with regard to gripping forces and complexity of application. Modelling of the forces is executed for separation distances in the range of 1x10 -12 m - 1x10 -3 m. Even though vacuum forces dominate in magnitude over others within the whole range, there are several disadvantages of using them. On the other hand adhesive forces are advantageous in that they require little amount of energy and they do not mechanically strain the micro-parts being handled.