Kaitlyn P. Becker

Abstract Soft grippers, used in applications such as food handling and assistive devices, leverage multiple soft fluidic actuators (SFAs) for safe and compliant grasping. Designing SFAs is challenging because they must satisfy multiple functional requirements while operating outside the principles of rigid machine design, as they undergo large deformations and exhibit material nonlinearity. Because fabricating numerous design candidates is costly, computational tools have emerged to expedite the search for optimal designs. However, existing computational tools do not focus on SFA design optimization for state-specific grasping, where actuators are optimized for a particular deformation dictated by the intended use case. Moreover, many existing tools support a limited range of performance metrics and optimization modes. Here, we present PneuGrasp, an open-source tool for the design optimization of SFAs according to a user-specified grasping task. The tool can analyze design candidates across multi-functional combinations of seven performance metrics, including the understudied metrics of grasping force, actuation speed, and actuation energy. In addition, PneuGrasp supports three optimization modes that together provide parameter intuition and shorten optimization time. Through a series of examples evaluating over 1000 design candidates, we demonstrate that PneuGrasp can identify optimized designs that outperform our baseline. For instance, one design achieved a 60% reduction in maximum strain and a 52% reduction in actuation volume, while another showed a 405% decrease in a combined durability–grasping–force performance score. We fabricated and tested over 30 actuators across five distinct designs, demonstrating PneuGrasp’s relative prediction capabilities. PneuGrasp can be found online.

Barriers to the widespread adoption of robots often stem less from limitations in technical capability than from the social, cultural and interpretive contexts in which these systems are encountered. We therefore argue that aesthetics should be treated as a core design dimension, alongside functionality and safety, to support meaningful and situated human–robot interactions.

The soft robotics field is moving toward increasingly complex and integrated systems, which will contain interfaces between soft components and other soft, compliant, and/or rigid components. Although many soft interfaces leverage adhesion, soft robot designers currently have limited information for selecting appropriate materials and fabrication techniques. Through experimental testing, this article characterizes how the substrate material and bonding process influence the performance of soft-soft silicone [i.e., polydimethylsiloxane-based interfaces], provides a framework for approaching this analysis, and contextualizes the data to provide initial insights into material selection for soft-soft interfaces by showing how the data could be used to guide design decisions. Specifically, this article characterizes five addition-curing silicone rubbers and five bonding processes, and it defines performance using quantitative metrics relating to desirable qualitative behaviors: toughness (adhesive fracture energy), flexibility (maximum localized strain during peeling), and strength (ratio of initial-to-average force and magnitude of initial peak peel force). Together, the substrate material and bonding method jointly determine the failure behavior of soft-soft silicone interfaces, influencing both the achievable performance (toughness, strength, flexibility) and characteristic failure modes (adhesive, cohesive, mixed-mode). Understanding characteristic failure modes can inform design strategies to mitigate interfacial failure, enabling higher-capability soft robots with improved operating loads and component lifetimes.

Abstract Extreme design (XD) is a proposed research framework addressing engineering design's outer edges of complexity and uncertainty. As the scale and urgency of global challenges grow, such as climate change, autonomous systems, and aging populations, so does the need for design approaches that go beyond conventional methods and models. XD offers a way to approach design problems that are dynamic, interdisciplinary, and fundamentally hard to frame but have humanity at their core. This editorial introduces XD as a framework for developing new theories, methods, and tools suited to extreme conditions. It outlines research opportunities in adaptive systems, creative processes, multiscale prototyping, convergent collaboration, and sustainability. A complexity–uncertainty matrix positions XD relative to conventional and emerging design approaches. We aim to open a conversation—not to define XD fully, but to signal its necessity and invite the design research community to explore and shape it. The challenges ahead will not be solved by incremental improvement in how we approach design. They will require something new. We feel XD is a step in that direction.

Undergraduate engineering curriculum has commonly struggled to capture students’ imagination and in®terest for manufacturing. Curriculum in most undergraduate engineering programs give students limited opportunities to learn manufacturing. And if provided, manufacturing knowledge is often offered in one course near the end of the four-year degree – after significant career exploration has already passed. To stimulate students’ interest in manufacturing earlier in their undergraduate programs, we present the development and implementation of a LEGO®-themed freshman manufacturing course. The course is composed of interactive lectures, hands-on labs, factory visits, and team project-based learning. We integrated LEGOs throughout the curriculum as a medium to explore topics from prototyping to large-scale pr® for freshmen students in the spring of 2024 in a mechanical engineering program at MIT. Findings from implementing the Student Assessment of Learning Gains survey yield gains in attitudes, understanding, and skills in manufacturing. Finally, while manufacturing programs are traditionally predominantly male, the class’s enrollment was 75 % women, demonstrating the course’s promise to facilitate interest in manufacturing with a diverse audience.

Despite its various potential uses, untethered pneumatics have little practical use due to the speed, power, and controllability limitations of power systems, and system-design restrictions (dead volume contained in pneumatic circuits and hardware needed to handle high actuator pressures). In this work, we present a compact monopropellant engine that localizes pressure generation to actuators. Our approach minimizes dead volume by eliminating pneumatic circuitry and allows high-pressure actuation from a low-pressure fuel source. We introduce the architecture, present a hardware implementation, and prove our pressure-amplification working principle experimentally. We also experimentally demonstrate fast response time (<30ms), high-pressure capability (>100kPa), high flow rate capacity 140 SLM/kg), and the ability to control the rate of gas output and volume of produced gas. Finally, we interface the engine with two distinct soft actuators to demonstrate its plug-and-play ease of use, operating at both high speeds and high pressures, and estimating a promising power output range (~5-25W/kg). With this design, we hope to move closer towards self-contained pneumatic muscles that interface with low-pressure embodied energy storage, which may increase the viability of pneumatic actuation for untethered robotic applications.

Abstract Mechanical metamaterials—structures with unusual properties that emerge from their internal architecture—that are designed to undergo large deformations typically exploit large internal rotations, and therefore, necessitate the incorporation of flexible hinges. Kirigami structures, made by introducing ordered cuts in a planar material, are one such example. In the mechanism limit, these structures consist of rigid bodies connected by ideal hinges that deform at zero energy cost. However, fabrication in this limit has remained elusive. Here, we demonstrate that the integration of textile hinges provides a scalable platform for creating large kirigami metamaterials with mechanism‐like behaviors. Further, leveraging recently introduced kinematic optimization tools, we show that textile hinges enable extreme shape‐morphing responses, paving the way for the next generation of mechanism‐based metamaterials.

Abstract In comparison to traditional glass casting, glass additive manufacturing (AM) presents an opportunity to increase design flexibility and reduce tooling costs for the production of highly variable geometries. While the latter has been extensively explored for masonry units, there is minimal research on the former for its viability to produce structural building components. This paper encompasses design, manufacturing, and experimental testing to assess the feasibility of using glass AM to produce interlocking masonry units for the construction industry. The glass 3D printer employed in this study is capable of printing a maximum volume of 32.5 $$\times $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>×</mml:mo> </mml:math> 32.5 $$\times $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>×</mml:mo> </mml:math> 38 cm–suitable for producing full-size masonry units. As part of this work, we discuss how to adapt design guidelines for glass AM to produce interlocking units. To evaluate fabrication ease and structural performance, three fabrication methods, Fully Hollow, Print-Cast, and Fully Printed, are compared. To compare the accuracy, repeatability, and structural capacity of each masonry unit, geometric analysis, surface roughness, and mechanical testing is conducted. Results varied by fabrication method, with average strength ranging from 3.64 $$-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>-</mml:mo> </mml:math> 42.3 MPa for initial fracture and 64.0–118 MPa for ultimate strength. Accuracy in print dimensions was less than 1 mm with a standard deviation of 0.14–1.6 mm. Results demonstrated that Fully Hollow masonry units provide a more immediate path to implementation, while Fully Printed units have the potential to provide an entirely glass, transparent, and circular building component fabrication method.

Counter-bending is a bio-inspired passive behavior that has been observed in the whip-like flagella of many microorganisms and cells. Counter-bending beams passively bend toward and conform around applied forces. Counter-bending behavior is particularly interesting in soft robotic grasping as it offers passive adaptability to objects in contact. The mechanism behind counter-bending behavior has been proposed as models and inspired compliant grasper designs in previous works; yet, existing designs only realize 2D counter-bending, which limits the adaptability to one direction. 3D counter-bending fingers can expand their adaptability to objects with wider range of geometries, and the unique constraints enforced by the 3D counter-bending beam can also be exploited in other applications such as coupling mechanisms and underactuated underwater locomotion. However, a physical realization of 3D counter-bending beam has yet to be proposed. In this paper, we employ continuum topology optimization to search for a beam structure capable of 3D counter-bending. The topology optimizer 1) validates existing 2D counter-bending model, and 2) generates a 3D structure that provides insight into prototyping a 3D counter-bending beam. To validate the structure from optimization results, we prototype a 3D counter-bending beam using inextensible wires and soft elastomers, and we assemble 3D counter-bending fingers into an underactuated grasper to demonstrate the adaptability to objects with distinct geometries enabled by the counter-bending capability.

Abstract This study introduces the low‐volume core (LVC) fabrication method, which enables the monolithic molding of compact, complex, versatile, and intelligent soft robotic systems. This method uses thin and flexible thermoplastic sheets to mold internal chambers in soft fluidic actuators, valves, and circuits. The LVC fabrication method creates low‐volume networks in soft actuators (LV‐net actuators) that can be made with compact and complex geometries, enabling both low actuation volume input and multi‐degree‐of‐freedom actuators. LVC fabrication can also be used for compact, completely soft, and monolithic logic components (valves with low‐volume core, also called as LV valves) to provide directional resistance as well as a switching mechanism that enables fluidic logic in soft systems. The compatibility of the fabrication methods for both soft actuators and valves facilitates the creation of compact, integrated, and versatile soft robotic systems with embodied intelligence. This study introduces two examples of such intelligent soft robotic systems that integrate both LV‐net actuators and LV valves to demonstrate capability for complex system fabrication.

We present 4k video and whole transcriptome data for seven deep-sea invertebrate animals collected in the Eastern Pacific Ocean during a research expedition onboard the Schmidt Ocean Institute's R/V Falkor in August of 2021. The animals include one jellyfish (Atolla sp.), three siphonophores (Apolemia sp., Praya sp., and Halistemma sp.), one larvacean (Bathochordaeus mcnutti), one tunicate (Pyrosomatidae sp.), and one ctenophore (Lampocteis sp.). Four of the animals were sequenced with long-read RNA sequencing technology, such that the reads themselves define a reference assembly for those animals. The larvacean tissues were successfully preserved in situ and has paired long-read reference data and short read quantitative transcriptomic data for within-specimen analyses of gene expression. Additionally, for three animals we provide quantitative image data, and a 3D model for one siphonophore. The paired image and transcriptomic data can be used for species identification, species description, and reference genetic data for these deep-sea animals.

One of the major challenges in the design and construction of soft-rigid hybrid systems is having robust bonding at soft-rigid interfaces. Soft robots tend to be compliant and adaptive but weak, while rigid robots tend to be strong and precise but uncompromising. Soft-rigid hybrid systems can provide a blend of both compliant interactions with environments as well as fast and precise body position controls. In this paper, we propose a fabrication strategy using flocking to achieve strong bonding between soft and rigid parts. Flocking is a fabrication method that bonds short fibers to fabrics or plastics. The fibers create a fuzzy surface texture on rigid components, which increases the surface area. In the context of soft robotic molding, flocked surface texture increases mechanical bonding between soft and rigid components and enables incorporation of rigid components with increased complexity or challenging placement that could be overmolded but not glued. In this paper, we investigate design parameters for flocking such as substrate materials, adhesives, and flocking materials; we recommend design and fabrication guidelines for the use of flocking to incorporate printed ABS and PLA components in silicone. To demonstrate the utility of flocking in a range of soft systems, we have fabricated several example soft systems with integrated components, including a pneumatic network (pneu-net) actuator, soft chambers connected to semi-rigid tubing, and a sensorized soft actuator. The performance of these demonstrations was comparable or exceeded that of silicone glues and allows for direct overmolding of complex structures, making flocking applicable and versatile in soft-rigid hybrid systems.

Revolutionary advancements in underwater imaging, robotics, and genomic sequencing have reshaped marine exploration. We present and demonstrate an interdisciplinary approach that uses emerging quantitative imaging technologies, an innovative robotic encapsulation system with in situ RNA preservation and next-generation genomic sequencing to gain comprehensive biological, biophysical, and genomic data from deep-sea organisms. The synthesis of these data provides rich morphological and genetic information for species description, surpassing traditional passive observation methods and preserved specimens, particularly for gelatinous zooplankton. Our approach enhances our ability to study delicate mid-water animals, improving research in the world's oceans.

We present an additive approach for the inverse design of kirigami-based mechanical metamaterials by focusing on the empty (negative) spaces instead of the solid tiles. By considering each negative space as a four-bar linkage, we identify a simple recursive relationship between adjacent linkages, yielding an efficient method for creating kirigami patterns. This allows us to solve the kirigami design problem using elementary linear algebra, with compatibility, reconfigurability and rigid-deployability encoded into an iterative procedure involving simple matrix multiplications. The resulting linear design strategy circumvents the solution of a non-convex global optimization problem and allows us to control the degrees of freedom in the deployment angle field, linkage offsets and boundary conditions. We demonstrate this by creating a large variety of rigid-deployable, compact, reconfigurable kirigami patterns. We then realize our kirigami designs physically using two simple but effective fabrication strategies with very different materials. Altogether, our additive approaches present routes for efficient mechanical metamaterial design and fabrication based on ori/kirigami art forms. Kirigami is an ancient art form that is now increasingly studied and applied in science and technology. This work presents an additive approach for the computational design of kirigami and two fabrication strategies for its physical instantiation.