Controllable and reversible tuning of material rigidity for robot applications

Wang, Li-Yu; Yang, Yang; Chen, Yonghua; Majidi, Carmel; Iida, Fumiya; Askounis, Erin; Pei, Qibing

doi:10.1016/j.mattod.2017.10.010

Cited by 168 publications

(146 citation statements)

References 97 publications

Supporting

Mentioning

145

Contrasting

Order By: Relevance

“…Among many phase change materials (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), including shape memory polymers (7)(8)(9)20), phase change metals (e.g., low-melting point alloys) (10)(11)(12)(13), and magnetorheological (14,15) and electrorheological fluids (16), gallium is one of the most attractive options for the transformative platform involving biological applications because of its biocompatibility, high elastic modulus (9.8 GPa), and ideal melting temperature (29.8°C) (21,22), which makes it solid at room temperature (22° to 25°C) and liquid at the temperature of biological tissue (32° to 37°C). By being embedded in a soft polymer, similar to what have been reported by recent studies on variable stiffness devices (10,12,23), the meltable and freezable features of gallium en-able large rigidity tuning (between a few tens of kPa and ~10 GPa) when applied to or detached from tissue.…”

Section: Design Materials and Mechanicsmentioning

confidence: 99%

Mechanically transformative electronics, sensors, and implantable devices

et al. 2019

View full text Add to dashboard Cite

Traditionally, electronics have been designed with static form factors to serve designated purposes. This approach has been an optimal direction for maintaining the overall device performance and reliability for targeted applications. However, electronics capable of changing their shape, flexibility, and stretchability will enable versatile and accommodating systems for more diverse applications. Here, we report design concepts, materials, physics, and manufacturing strategies that enable these reconfigurable electronic systems based on temperature-triggered tuning of mechanical characteristics of device platforms. We applied this technology to create personal electronics with variable stiffness and stretchability, a pressure sensor with tunable bandwidth and sensitivity, and a neural probe that softens upon integration with brain tissue. Together, these types of transformative electronics will substantially broaden the use of electronics for wearable and implantable applications.

show abstract

Section: Design Materials and Mechanicsmentioning

confidence: 99%

Mechanically transformative electronics, sensors, and implantable devices

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Recent studies in soft robotics have focused on the use of tunable‐stiffness materials to achieve various Young's moduli . These materials can be transformed between liquid and solid phases by controlling a magnetic field or the temperature.…”

Section: Tunable Stiffness In Soft Medical Robotsmentioning

confidence: 99%

“…There are still many other tunable‐stiffness materials that can be used to change the stiffness. However, these materials are rarely applied to soft medical robots due to the limiting factors of biocompatibility and security . The tunable‐stiffness based on MRFs is a promising approach for the precise control of damping.…”

Section: Tunable Stiffness In Soft Medical Robotsmentioning

confidence: 99%

A review of recent advancements in soft and flexible robots for medical applications

Zhang

2020

Robotics Computer Surgery

View full text Add to dashboard Cite

Background: Soft and flexible robots for medical applications are needed to change their flexibility over a wide range to perform tasks adequately. The mechanism and theory of flexibility has been a scientific issue and is of interest to the community. Methods: Recent advancements of bionics, flexible actuation, sensing, and intelligent control algorithms as well as tunable stiffness have been referenced when soft and flexible robots are developed. The benefits and limitations of these relevant studies and how they affect the flexibility are discussed, and possible research directions are explored. Results: The bionic materials and structures that demonstrate the potential capabilities of the soft medical robot flexibility are the fundamental guarantee for clinical medical applications. Flexible actuation that used to provide power, intelligent control algorithms which are the exact executors, and the wide range stiffness of the soft materials are the three important influence factors for soft medical robots. Conclusion: Some reasonable suggestions and possible solutions for soft and flexible medical robots are proposed, including novel materials, flexible actuation concepts with a built-in source of energy or power, programmable flexibility, and adjustable stiffness. K E Y W O R D S bionics, flexible actuation, sensing and intelligent control algorithm, soft and flexible robots, tunable stiffness 1 | INTRODUCTION The application of robots in the medical field dates back to a few decades ago, but the recent use of soft materials in medical robots has enabled new capabilities that create possibilities for medical treatments in which much safer human-robot interaction is preferred. 1-3 Soft medical robots are defined as soft and flexible electro-mechanical systems with high flexibility performing medical applications. Soft medical robots are multidisciplinary emerging technologies 4 such as materials science, bionics, mechanics, electronics, and computer science. At present, soft medical robots have been used for surgery, 5diagnosis, 6 rehabilitation, 7 prostheses, 8 artificial organs, 9 drug delivery 10 and many other medical applications. [11][12][13][14][15][16] The movements such as bending, torsion, extension, and contact operations 17 required high flexibility and deformability 18 of soft medical robots.Soft medical robots exhibit a range of degrees of flexibility during medical applications. In this paper, flexibility is used to describe the characteristics of soft medical robots that have a proper combination of stiffness and compliance and it is on the scientific level. Actually, flexibility reflects in three aspects: the variety of shape, the wide range of stiffness, and the adequate force applied. It is necessary for soft medical robots that it can change their flexibility degree over a wide range to perform tasks adequately. For example, there has certainly been a longterm demand in minimally invasive surgery (MIS) applications for soft medical robots that can move, deform, navigate narrow gaps, and int...

show abstract

“…This is of particular concern in surgical manipulators which, on the one hand, need to be soft to avoid damaging tissue when accessing the surgical site, but on the other, need to be stiff enough to make incisions. In response to these contradicting requirements, researchers have examined techniques for actively changing the stiffness of compliant devices [100]. The most direct approach to actively controlling stiffness relies on using antagonistic actuation, where two actuation systems exert opposing forces.…”

Section: Active Compliancementioning

confidence: 99%

“…The authors speculate that these properties could be harnessed when designing new types of morphological computational element. A previous review has examined how some materials can be used to alter the stiffness of some structures [100], all of which are excellent candidates for such research. Furthermore, ref.…”

Section: Potential Topics Of New Researchmentioning

confidence: 99%