Purpose – This study aims to investigate the potential of using polymer multi-material additive manufacturing (MMAM) to produce miniature hydraulic piston actuators combining rigid structures and flexible seals. Such actuators offer great potential for medical robots in X-ray and magnetic resonance environments, where conventional piston actuators cannot be used because of safety issues caused by metal components. Design/methodology/approach – Hydraulic pistons with two different integrated flexible seal shapes are designed and manufactured using MMAM. Design 1 features a ring-shaped seal made from a flexible material that is printed on the surface of the rigid piston shaft. Design 2 appears identical from the outside, yet an axial opening in the piston shaft is added to enable self-reinforced sealing as fluid pressure increases. For both designs, samples with three different outer diameters are fabricated leading to a total of six different piston versions. The pistons are then evaluated regarding leakage, friction and durability. Findings – Measurement results show that the friction force for Design 2 is lower than that of Design 1, making Design 2 more suitable for the intended application. None of the versions of Design 2 shows leakage for pressures up to 1.5 MPa. For Design 1, leak-tightness varies with the outer diameter, yet none of the versions is consistently leak-tight at 1.5 MPa. Furthermore, the results show that prolonged exposure to water decreases the durability of the flexible material significantly. The durability the authors observe may, however, be sufficient for short-term or single-use devices. Originality/value – The authors investigate a novel design approach for hydraulic piston actuators based on MMAM. These actuators are of particular interest for patient-specific medical devices used in radiological interventions, where metal-free components are required to safely operate in X-ray and magnetic resonance environments. This study may serve as a basis for the development of new actuators, as it shows a feasible solution, yet pointing out critical aspects such as the influence of small geometry changes or material performance changes caused by water absorption.


    Access

    Download


    Export, share and cite



    Title :

    Multi-material 3D printed hydraulic actuator for medical robots


    Contributors:

    Publication date :

    2020-01-01


    Remarks:

    Fraunhofer IPA



    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Classification :

    DDC:    600 / 629



    HYDRAULIC ACTUATOR AND MULTI-CYLINDER HYDRAULIC ACTUATOR SYSTEM

    KRACKE JEREMY | European Patent Office | 2019

    Free access

    Multi-action hydraulic actuator

    QIU YONGNING / XUE HUAXIA / WANG WEITANG et al. | European Patent Office | 2022

    Free access

    MULTI-CYLINDER HYDRAULIC ACTUATOR SYSTEM

    KRACKE JEREMY | European Patent Office | 2020

    Free access

    Integrated multi-actuator electro-hydraulic unit

    BELTER JOSEPH THOMAS / TUCKER CLIVE / GIOVANARDI MARCO et al. | European Patent Office | 2023

    Free access

    HYDRAULIC ACTUATOR

    European Patent Office | 2015

    Free access