Hybrid Two-Scale Fabrication of Sub-Millimetric Capillary Grippers

Abstract

Capillary gripping is a pick-and-place technique that is particularly well-suited for handling sub-millimetric components. Nevertheless, integrating a fluid supply and release mechanism becomes increasingly difficult to manufacture for these scales. In the present contribution, two hybrid manufacturing procedures are introduced in which the creation of the smallest features is decoupled from the macro-scale components. In the first procedure, small scale features are printed directly (by two-photon polymerisation) on top of a 3D-printed device (through stereolithography). In the second approach, directional ultraviolet (UV)-illumination and an adapted design allowed for successful (polydimethylsiloxane, PDMS) moulding of the microscopic gripper head on top of a metal substrate. Importantly, a fully functional microchannel is present in both cases through which liquid to grip the components can be supplied and retracted. This capability of removing the liquid combined with an asymmetric pillar design allows for a passive release mechanism with a placement precision on the order of 3% of the component size.

3D-Printed MEMS in Italy

“…Another interesting application of TPP technology in the MEMS world is represented by the work of Dehaeck et al [ 45 ], which fabricated microgrippers that relied on capillary force to grip the component. The presence of a liquid layer helps the components to maintain a scratch-free surface, and it also excludes the influence of surface irregularities on the grip force.…”

Miniaturized Robotics: The Smallest Camera Operator Bot Pays Tribute to David Bowie

“…It enables to print highly cantilevered figurines such as the figurine described on figure 9(l). This know-how is now used currently to print microdevices and especially microgrippers [13]. The film has also provided new robotic capabilities by developing a complete software that enables to perform high precision positioning in a semi-automatic mode when the current SEM micromanipulators in the world is only teleoperated.…”

Two-dimensional modelling of transient capillary driven damped micro-oscillations and self-alignment of objects in microassembly

“…2020), variation of wettability (Fantoni, Hansen & Santochi 2013), on liquid volume control through 3-D printed and replicated microchannels (Dehaeck et al. 2019), or finally based on electrowetting as introduced by Apoorva, Maccurdy & Lipson (2014) and Vasudev et al. (2009).…”

“…Without aiming to be exhaustive on the technical capillary handling and assembly solutions, we may, however, give a few examples. Some of these capillary grippers are based on water condensation and temperature variations (Uran, Safaric & Bratina 2017), on laser evaporation and changes in the contact conformity (Iazzolino et al 2020), variation of wettability (Fantoni, Hansen & Santochi 2013), on liquid volume control through 3-D printed and replicated microchannels (Dehaeck et al 2019), or finally based on electrowetting as introduced by Apoorva, Maccurdy & Lipson (2014) and Vasudev et al (2009). High-speed self-assembly lines using capillary forces are presented by Knuesel & Jacobs (2010) and Park et al (2015).…”