Multiflexible micromanipulator design by using topology optimization

In the MEMS scale the presence of joints and pins must be avoided due to manufacturing constraints. This makes difficult to design micromechanisms with many degrees of freedom to perform complex movements, such as micromanipulators or micro-robots. However, these microdevices can have a wide range of application such as cell manipulation, microsurgery, nanotechnology equipment,etc. Therefore, in this work, a method for designing multiflexible micromanipulators is proposed by using topology optimization technique based on the homogenization design method. Micromanipulators considered in this work consist of a multiflexible structure actuated by two or more piezoceramics. A multi-flexible structure must generate different output displacements and forces in different specified points of the domain and directions, for different excited piezoceramics. It acts as a mechanical transform by amplifying and changing the direction of the piezoceramics output displacements. The multiflexible structure design is obtained by distributing flexibility and stiffness in the design domain, which can be achieved through topology optimization. Essentially, the topology optimization method consists of finding the optimal material distribution in a perforated design domain with infinite microscale voids. The material in each point can vary from void to full material, also assuming intermediate materials. The optimization problem is posed as the design of a flexible structure that maximizes different output displacements (or grabbing forces) in different specified directions and points of the domain, for different excited piezoceramics. Different types of micromanipulators can be obtained for a desired application depending on the multiflexible structure design connected to the piezoceramics. A linear behavior of piezoceramics is considered. To illustrate the method, the design of some micromanipulators are presented.