Shape-Conformable Suction Cups With Controllable Adaptive Suction on Complex Surfaces

Abstract

Suction is widely used in industry, but the adaptation of state-of-the-art suction cups on complex surfaces (i.e., curved, cornered, uneven, rough, etc.) are still limited. In this letter, we present a novel shape-conformable suction mechanism to achieve highly-adaptive suction on complex surfaces. The shape-conformable adaptive suction is obtained by squeezing a soft multi-layer structure on the substrate, to form a shape-to-roughness sealed suction region. Based on this mechanism, two shape-conformable suction cups (SCSCs) – a displacement-driven shape-conformable suction cup ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\text{S}_\text{Disp}$</tex-math></inline-formula> ) and a force-driven shape-conformable suction cup ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\text{S}_\text{Force}$</tex-math></inline-formula> ) – are designed. They both achieve highly-adaptive suction on challenging surface topographies including highly-curved, cornered, textured, uneven and tilted surfaces. Particularly, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\text{S}_\text{Disp}$</tex-math></inline-formula> has better adaptation (e.g., on a 90 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> corner and a balloon) and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\text{S}_\text{Force}$</tex-math></inline-formula> is more lightweight (26 g) and compact ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\varnothing 46\times 35$</tex-math></inline-formula> mm), and exhibits quicker suction response (0.4 s). We analyse the underlying adaptive suction mechanism by the physical model, and demonstrate its adaptive suction capability by qualitatively comparing it with previous suction cups. We finally conclude design principles for improving suction adaptation. We believe the proposed shape-conformable suction mechanism provides a novel solution to realize adaptive suction on complex surfaces in next-generation robotic gripping, anchoring, and manipulation.