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Page 24 of 35 Kulkarni et al. Soft Sci. 2025, 5, 12 https://dx.doi.org/10.20517/ss.2023.51

Self-healing capability is also a unique advantage of some soft materials that can increase operation time in
challenging environments where retrieval and repair are difficult.

However, soft robots also have drawbacks. They are less powerful and precise than rigid devices due to
being made of much softer and, in some cases, weaker materials. The properties of these materials, such as
extensional stiffness, strength, and elasticity, can be improved through reinforcement with rigid materials
[300]
[301]
such as fibers . These hybrid materials offer enhanced capabilities, expanding the reach of soft and hybrid
robots in extreme environments. Additionally, soft robots are difficult to model and control due to their
nonlinear properties and lack of a supporting structure.

As observed in nature, most fully soft organisms are small, and if larger, need a skeleton to support their
[12]
weight . Large, soft animals without skeletons typically exist in water or underground so that their bodies
are supported by the surrounding medium. This evidence suggests that the best systems may be an
integration of rigid structures and soft technologies. Thus, new types of hybrid structures have evolved that
can withstand and exert more force than simple soft robots, increasing their applications in industrial
settings . Developing controllers and stable interfaces between the soft and rigid components is necessary
[302]
in future research to control the upcoming hybrid devices . Hybrid system interactions are also generally
[302]
required for actuator control since soft elastic materials would require rigid microprocessors until the time
microelectronics can be fully made of low-modulus and elastic materials.

Since rigid robots dominate in use and availability, we see opportunities to expand the potential of soft
robots in extreme environments. This can be accomplished using design techniques such as topology
optimization that can improve the efficiency, cost, and material savings, and the tunability of actuator
design. Implementing control systems with AI and machine learning may allow for more robust control of
complex nonlinear behaviors and better decision-making. Finally, soft robots must be expanded by
designing with the end user in mind by increasing accessibility, and usability, and reducing cost. Other ways
to enhance the scope of these soft devices include improving operational lifetime with durable, self-healing,
elastic materials and building entire structural components including electronics and power units from
sustainable materials to minimize environmental impact. Thus, there is significant potential to advance soft
robots in harsh environments, and future studies must accelerate the transition of high-performance soft
devices from research labs to real-world applications.

DECLARATIONS
Acknowledgments
The authors thank the Clare Boothe Luce (CBL) Research Scholars and the Grainger College of
Engineering. This work was partially conducted at the Center for Integrated Nanotechnologies, an Office of
Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National
Laboratories is a multimission laboratory managed and operated by National Technology & Engineering
Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE’s
National Nuclear Security Administration under contract DE-NA-0003525. The views expressed in the
article do not necessarily reflect those of the U.S. DOE or the U.S. Government.

Authors’ contributions
Conceptualization: Kulkarni, M., Golecki, H.
Writing: Kulkarni, M., Edward, S., Golecki, T., Kaehr, B., Golecki, H.
Visualization: Edward, S., Golecki, H.