Generating Secure and Gentle Grip on Soft Substrates

Generation of grip on soft tissue in the surgical field is most commonly done with forceps that generate friction grip, that is, the translation of normal (pinch) forces into shear forces. Errors made with these surgical grippers are often force-related: applying too low pinch forces results in slipping of the tissue out of the gripper, and too...

Implementation of anisotropic soft pads in a surgical gripper for secure and gentle grip on vulnerable tissues

Current surgical grippers rely on friction grip, where normal loads (i.e. pinch forces) are translated into friction forces. Operating errors with surgical grippers are often force-related, including tissue slipping out of the gripper because of too low pinch forces and tissue damaging due to too high pinch forces. Here, we prototyped a...

Design of Tree-Frog-Inspired Adhesives

The adhesive toe pads of tree frogs have inspired the design of various so-called 'smooth' synthetic adhesives for wet environments. However, these adhesives do not reach the attachment performance of their biological models in terms of contact formation, maintenance of attachment, and detachment. In tree frogs, attachment is facilitated by...

Effect of lateral reinforcements on the adhesion and friction of micropillar adhesives

Micropillar adhesives have gained increasing attention because they generate high pull-off forces. The generation of high friction, however, has been proven difficult with such geometries, because micropillars tend to buckle under shear loading. Here, we fabricated orthogonal arrays of composite poly-dimethoxysiloxane (PDMS) micropillars with...

Anisotropic Stiffness Adhesives for High Shear Forces on Soft Substrates

Reversible attachment on soft substrates is useful in a range of applications, including soft robotics and soft-tissue surgical instrumentation. On rigid substrates, the use of micropatterned adhesives has been extensively explored. It has been shown that surface micropatterns provide conformability, thereby enabling the formation and...

Pull-off and friction forces of micropatterned elastomers on soft substrates: The effects of pattern length scale and stiffness

The adhesiveness of biological micropatterned adhesives primarily relies on their geometry (e.g., feature size, architecture) and material properties (e.g., stiffness). Over the last few decades, researchers have been mimicking the geometry and material properties of biological micropatterned adhesives. The performance of these biomimetic...

Nanostructure and microstructure fabrication: From desired properties to suitable processes

When designing a new nanostructure or microstructure, one can follow a processing-based manufacturing pathway, in which the structure properties are defined based on the processing capabilities of the fabrication method at hand. Alternatively, a performance-based pathway can be followed, where the envisioned performance is first defined, and...