Manual microassembly system with integrated squeegee device for homogenous and defined adhesive layers for bimorph piezoelectric actuators using in drop-on-demand techniques

This paper describes a squeegee device for a manual microassembly system. The device consists basically of a height axis, of a squeegee clamp, and of a squeegee blade. The squeegee device is connected via a supporting arm to the base frame of a microassembly system. The objective of this work is to obtain a homogenous, thin, and defined adhesive layer for piezoelectric actuators which are used in microdroplet generators. Here, a droplet is ejected due to the bending of the actuator into a fluid filled chamber. The actuators are mostly based on bi-or multimorphic layer structures. Here, two or more layers, of which at least one is a piezoelectric material, are glued together. In this connection homogenous and thin adhesive layers are indispensable. The thinner this layer, the higher the bending of the actuator due to its reduced bending stiffness. As a result, more energy can be supplied to the droplet generation process. In this project two adhesives - one - as well as two-component - are used for the validation of the device. This shows that this device can work with different materials. The result is that homogenous adhesive layers between 10 μm and 80 μm can be spread homogenously onto substrates.