Overview

In his enlightening presentation, Prof. Keplinger detailed the innovative field of soft robotics, focusing on the development of artificial muscles to enhance the agility and dexterity of robots. Drawing inspiration from the natural design and efficiency of the human muscular system, Keplinger and his team have been pioneering the use of soft, fluidic components to simulate the functionality of biological muscle. His research has led to the creation of HASEL (Hydraulically Amplified Self-Healing Electrostatic) artificial muscles; these actuators are inexpensive, versatile, and capable of delicate tasks like lifting a raspberry as well as powerful actions such as shooting balls into the air. Keplinger shared his excitement about the potential of soft robotics in practical applications, notably in creating more lifelike prosthetics and assisting the elderly to maintain their independence. He concluded by suggesting that soft robotics could signify a next stage in human evolution, stressing the importance of interdisciplinary collaboration in this nascent field to improve the quality of life for everyone.

During his compelling TED Talk, Christoph Keplinger, a pioneer in the field of soft robotics, shared his groundbreaking research on developing artificial muscles, intended to propel the future of robotics. He began by illustrating the limitations of current robotics, exemplified by the robot HUBO’s slow and rigid movements in a disaster response competition. This highlighted a stark contrast between the mechanical, rigid bodies of contemporary robots and the soft, adaptable structures of the human body. Keplinger stressed the necessity for a new generation of robots inspired by the softness and flexibility found in nature.

Keplinger’s fascination with biological muscles, which can heal after damage, adapt to various tasks, and provide feedback through sensory neurons, served as the foundation for his research. His goal was to create soft actuators or artificial muscles that could match the versatility and adaptability of biological muscles. He recounted an initial experiment inspired by a 19th-century publication by Wilhelm Röntgen on using electricity to cause changes in dielectric bodies, which sparked his interest in the field.

Progress in Keplinger’s research led to the development of HASEL (hydraulically amplified self-healing electrostatic actuators) artificial muscles during his time leading a lab at CU Boulder. These muscles use inexpensive materials and can perform delicate tasks such as picking up a raspberry without damage. HASELs can expand, contract, and even self-sense their position, imitating the movements of biological muscles closely.

Moreover, Keplinger demonstrated the potential of HASELs through various designs, including the Peano-HASEL actuators and the quadrant donut HASELs, which are capable of lifting weights significantly heavier than themselves and achieving superhuman speeds. These advancements promise the first technology to potentially match or even exceed the natural performance of biological muscles, compatible with large-scale manufacturing.

Highlighting the practical applications of this technology, Keplinger envisioned a future where soft robotic devices could offer more lifelike prosthetics, enhancing the quality of life for individuals who have lost limbs. He proposed the idea of merging human bodies with robotic parts not as a fear-inducing future but as a means to restore and enhance agility and dexterity, especially for the elderly, moving towards what he termed “robotics for antiaging.”

Keplinger concluded his talk with a call to action, inviting young people from diverse backgrounds to join the exciting journey of soft robotics. He emphasized the potential of this field to improve the quality of life for everyone, harnessing the inspiration from nature to shape the future of robotics.

Technological Advancements

Since 2019, the field of soft robotics has seen continued advancements, with significant emphasis on creating more lifelike and adaptable robotic systems. Progress has been made in developing sophisticated soft actuators and materials that mimic the properties of biological muscles—such as flexibility, self-healing, and sensitivity. Notable is the evolution of technologies such as HASEL (Hydraulically Amplified Self-healing Electrostatic) artificial muscles, which have been improved to provide more strength, faster response times, and greater energy efficiency. Development of HASEL (Hydraulically Amplified Self-healing Electrostatic) actuators for robotic applications really enhances the versatility and mimicks the adaptive qualities of human muscle. The research focused on combining the speed and efficiency of traditional actuators with the flexibility of fluidic muscles. These actuators improved the functionality of soft robotics by enabling more delicate and precise movements, such as picking up a raspberry without damage, as well as strong lifts, like raising a gallon of water. (link)

Figure 1. HASEL actuators operating as linear actuators and soft grippers. [1]

Peano-HASEL actuators represented a breakthrough in the design of soft actuators by emulating natural, muscle-like movements and allowing for multi-directional expansion and contraction. Their construction based on simple, low-cost materials paves the way for more accessible soft robotic applications. : The designs of quadrant donut HASELs expanded the capabilities of soft actuators further. Their distinctive shape and mode of operation allowed for rapid actions and the ability to propel objects with force, introducing new potential for dynamic robotic tasks. Through specific applications, HASELs attained contraction and reaction rates exceeding natural human muscle capability. Such speeds offer applications in scenarios requiring quick, repetitive movements that surpass human limitations.

While soft robotics technologies demonstrate immense potential, their current commercial availability is limited. HASEL actuators are a relatively young technology, and their application outside the laboratory is still in nascent stages. Ongoing research is required to ensure that soft robotics can withstand repeated use without significant degradation. The longevity of these systems is crucial for commercial viability, especially in industrial applications that demand continuous operation. Transitioning from prototype to high-volume production poses a significant barrier. The field requires manufacturing techniques that not only preserve the integrity and functionality of soft components but are also cost-effective at scale. As with any technology that operates close to or within human environments, stringent safety standards must be met. The medical application of soft robotics further amplifies this challenge, as regulatory hurdles are high and much work is needed to gain approvals. For soft robotics to be commercially successful, there must be a market willing to adapt to its benefits. Education and demonstration of soft robotics’ advantages over rigid systems are necessary to overcome inertia and skepticism in traditional industries.

To generally speak, soft robotics is an emerging field that offers exciting possibilities but requires further development and strategic approaches to overcome current barriers to commercialization.

Relationship Between HASELs and Polymeric Biomaterials

The topic of HASEL is not that related to polymeric biomaterials. However, there exists a subtle but potentially significant connection between the two fields. HASEL actuators, which draw inspiration from biological muscle, could benefit from the integration with polymeric biomaterials known for their biocompatibility and flexibility. These materials can mimic the properties of natural tissues and may enhance the functionality of HASELs in applications requiring interaction with biological systems, such as in biohybrid robots or prosthetics. Moreover, the development of self-healing polymers as part of the biomaterials spectrum aligns with the self-healing properties sought in HASEL actuators, suggesting a crossover of technology that could lead to advanced robotic systems with improved resilience and lifelike properties. By exploring the synergy between HASEL technologies and polymeric biomaterials, researchers could unlock new innovations in soft robotics that are more adaptable and suited for dynamic, real-world applications.