Direct laser written passive micromanipulator end-effector for compliant object manipulation

Micromanipulation tasks are usually carried out using simplistic tools such as rigid probes and needles. More sophisticated tools such as grippers are fragile, expensive and non-dexterous. This paper addresses some of the main challenges of manipulation at the micrometer scale, including robots with limited degrees of freedom, small range of available tools and open-loop control due to a lack of position sensors. This work presents a preliminary investigation into the viability of using the Direct Laser Writing and Two-Photon Polymerization microfabrication techniques for creating flexible micrometer-scale end-effectors. A novel compliant end-effector design is presented for closed-chain cooperative manipulation involving multiple micromanipulator robots. A visual servoing framework was also developed to allow the user to control the robots in a closed loop manner, with haptic feedback to help match the user´s input to the speed of the robots. Characterization of the new compliant manipulator was conducted and multi-robot configurations were tested to demonstrate the flexibility, robustness and increased workspace of the new design for both 2D and 3D object manipulation tasks.