Dear Colleagues,

Variable stiffness in physical interactions is a common feature in nature (i.e., tree–branch connections in flora, cartilage–bone connections in fauna), in our daily lives (i.e., hand–phone interaction while grasping; foot–ground interaction while walking), in our machines (e.g., human–robot interaction and wheel–ground interaction in our automobiles), and structures (e.g., electric cable–pylon connections). Therefore, it is fundamental to understand the behavior of the variable stiffness in physical interactions, from both hardware and software point of views, to develop innovative robotic devices and machines for daily use.

In this Special Issue, we would like to explore the variable stiffness in physical connections and interactions from a mechanical and control point of view. To this end, we welcome the submission of papers presenting new challenges in the control, design, and development of compliant machines, novel compliant mechanisms and systems, new robots and devices, and many other architectures and artefacts.

This Special Issue is open (but not limited) to the following topics:

• Compliant mechanisms;
• Biomechanics;
• Parallel mechanisms;
• Parallel manipulators;
• Micromachines;
• Cable-driven systems;
• Tendon-driven systems;
• Soft robotics;
• Machine design;
• Control systems;
• Flexure hinges;
• Variable stiffness systems.

Dr. Giovanni Gerardo Muscolo
Prof. Dr. Giuseppe Carbone
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Machines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• compliant mechanisms
• parallel mechanisms
• parallel manipulators
• micro-machines
• cable-driven systems
• tendon-driven systems
• soft robotics
• machine design
• control systems
• flexure hinges
• variable stiffness systems