Wednesday, October 15, 2025

Programming robots with rubber bands

New approach uses robot’s physical structure for function

Harvard John A. Paulson School of Engineering and Applied Sciences

Robot form — video:
Researchers created a physically intelligent robot through mechanical design alone.
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Credit: Harvard SEAS Communications

Key Takeaways

A Harvard team has demonstrated that robots can be designed to react to their environment and perform tasks by programming intelligence into their structure.
They created a robot capable of autonomously moving away from obstacles, with minimal electronics.
The work presents an alternative to traditional robotic sensing and control systems.

From sorting objects in a warehouse to navigating furniture while vacuuming, robots today use sensors, software control systems, and moving parts to perform tasks. The harder the task or more complex the environment, the more cumbersome and expensive the electronic components.

Mechanical engineering researchers in the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) think there’s another way to design robots: Programming intended functions directly into a robot’s physical structure, allowing the robot to react to its surroundings without the need for extensive on-board electronics.

A team from the lab of Katia Bertoldi, the William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS, designed a proof-of-concept walking robot with just four moving parts connected by rubber bands and powered by one motor. With its movements programmed via the placement of the rubber bands, the robot can find its way through mazes and avoid obstacles; its movements change based only on how it is touched or pressed by its environment, with no electronic brain. They also show that the same mechanical programming can be used to make a robot capable of sorting objects by mass.

The demonstration could spark new inquiry into fundamentals of robotic design, potentially leading to smaller, simpler robots that can perform a variety of functions.

Published in Proceedings of the National Academy of Sciences, the work was led by Leon Kamp, a graduate student in Bertoldi’s lab whose secondary graduate study is in Critical Media Practice. Trained in engineering and architecture, Kamp turned to robotics as a practical application of his interest in form, material, and mechanics. He wondered if robotic intelligence could be infused into structure using mechanical principles.

“This is kind of an extreme version of ‘form follows function,’ where functionalities like memory, adaptability and intelligence can be enabled by geometry and material parameters,” Kamp said.

Kamp and colleagues built their robotic mechanism from a chain of flat plastic blocks joined by levers and rubber bands. The stretching of the rubber bands assigns a certain energy cost to rotating each lever. The movement of the mechanism can be “programmed” as it follows the order of rotations that has the lowest energy cost. By attaching a leg to this mechanism, they built a robot that can walk forward and backward using one motor for different configurations of rubber bands.

This physical programming allows the robot to passively sense and respond to forces from its environment. It “feels” its surroundings via a pair of antennae attached to the front. When one antenna hits an obstacle, the robot responds and adapts from walking straight to turning away. It can autonomously navigate mazes or move away from obstacles.

In another configuration, the mechanism can be used to automatically sort objects based on their mass. In this case the rubber bands are used to “program,” where objects are picked up and dropped off at different locations for specific targeted masses.

While the mechanism can only accomplish a small number of simple tasks, the concept could be expanded to robots that move faster or jump over obstacles. In the future, robots like this could be made of flexible materials that are lightweight and easy to manufacture. Such designs could lead to autonomous machines that are physically intelligent and rely on fewer electronics or traditional control systems to function.

The paper was co-authored by Mohamed Zanaty, Ahmad Zareei, Benjamin Gorissen, and Professor Robert J. Wood. The research received federal support from the National Science Foundation through the Harvard Materials Research Science and Engineering Center grant (DMR-2011754) and the Army Research Office Multidisciplinary University Research Initiative program (W911NF-22-1-0219).

Watch: https://www.youtube.com/watch?v=wZKxr8COXBI

A robot fully controlled with rubber bands instead of electronic components.

Credit

Bertoldi Lab / Harvard SEAS

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2508310122

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Reprogrammable sequencing for physically intelligent underactuated robots

Innovations in organoid engineering: Construction methods, model development, and clinical translation

Xia & He Publishing Inc.

As a revolutionary 3D cell culture system, organoids bridge the gap between traditional 2D models and animal studies. This review synthesizes the current state of organoid engineering, from fundamental methods to transformative applications.

Organoid Construction
Key methods enable the generation of complex organoids:

Air-Liquid Interface (ALI) Culture: Ideal for modeling hollow organs and co-culturing with immune cells to study the tumor microenvironment.
Bioreactor Culture: Uses agitation to enhance nutrient exchange, supporting the growth of large, complex organoids like brains and enabling scalable production.
Vascularization: A critical advancement where organoids are integrated with blood vessels to improve survival and model neurovascular interactions.

Representative Models
The review details the construction of organoids for major organs, including kidneys, livers, lungs, brains, and intestines. These models are derived from pluripotent or adult stem cells using specific signaling pathways and scaffolds to recapitulate organ-specific structure and function.

Applications in Biomedicine
Organoids are transforming biomedical research:

Disease Modeling: They accurately mimic diseases like cancer, Zika virus infection, and cystic fibrosis.
Drug Screening & Biobanking: Patient-derived organoid biobanks allow for high-throughput drug testing and personalized treatment prediction.
Precision Medicine & Toxicity Assessment: They enable the selection of effective therapies for individual patients and provide human-relevant platforms for safety testing.

Application in TCM
Organoids offer a modern platform for TCM research, enabling the screening of active components, studying multi-target mechanisms, and evaluating the safety and efficacy of herbal compounds.

Frontier Technologies
The integration with cutting-edge technologies is pushing the field forward:

Gene Editing creates precise disease models.
Single-Cell RNA Sequencing reveals cellular heterogeneity.
3D Bioprinting allows for the precise fabrication of complex structures.
Artificial Intelligence analyzes complex organoid data for patterns and predictions.

Conclusion
Despite challenges in standardizing complexity and addressing costs, organoid technology is a powerful tool rapidly advancing our understanding of biology and disease. Its continued integration with other technologies promises to accelerate drug discovery and usher in a new era of personalized and integrative medicine.

Full text:

https://www.xiahepublishing.com/2835-6357/FIM-2025-00023

The study was recently published in the Future Integrative Medicine.

Future Integrative Medicine (FIM) is the official scientific journal of the Capital Medical University. It is a prominent new journal that promotes future innovation in medicine.It publishes both basic and clinical research, including but not limited to randomized controlled trials, intervention studies, cohort studies, observational studies, qualitative and mixed method studies, animal studies, and systematic reviews.

Journal

Future Integrative Medicine

DOI

10.14218/FIM.2025.00023

Article Title

Innovations in Organoid Engineering: Construction Methods, Model Development, and Clinical Translation

The largest primate in the Americas could lose up to 61% of its climatically suitable habitat by 2090

Study predicts that the two species of muriquis will be restricted mainly to coastal regions of the Atlantic Forest, leaving populations in the interior seriously at risk.

Fundação de Amparo à Pesquisa do Estado de São Paulo

The northern muriqui (Brachyteles hypoxanthus) and the southern muriqui (B. arachnoides) are the two species of the largest genus of primates in the Americas. A study published in the Journal for Nature Conservation with support from FAPESP estimates that their habitat will be reduced by 44% and 61%, respectively, by 2090. In São Paulo, Brazil, the northern muriqui is expected to lose its entire climatically suitable area by the end of the century.

These figures only account for the effect of climate change on the species by the end of the century. They do not consider other factors that threaten primates and their habitats, such as deforestation, forest fragmentation, and hunting. Both muriquis are endemic to the Atlantic Forest and are classified as “critically endangered” by the International Union for Conservation of Nature (IUCN) (read more at agencia.fapesp.br/53161).

“Climate change alone won’t lead to the extinction of muriquis, according to our projections. But about half of the current climatically favorable area for them could disappear, which is quite worrying considering that there are other factors putting pressure on these species,” says Tiago Vasconcelos, the author of the study and a researcher in the Graduate Program in Biosciences at the Bauru campus of São Paulo State University (UNESP).

The work is part of a project supported by FAPESP under the Research Program on Global Climate Change (RPGCC).

The projections are made using specialized software based on data such as the current distribution of muriquis and climate information that is important for their physiological requirements. Current climate data are thus used to characterize the species’ preferences, which are then projected into different future climate change scenarios for the coming decades, such as changes in rainfall, warmer months, and drier days.

Challenge in the interior

Previous studies by other researchers had already indicated that climatically suitable areas for the two species of muriqui would be lost by the end of the century. However, Vasconcelos points to the extent of the damage in the short and medium term, specifically by the years 2030, 2050, 2070, and 2090.

“Other authors had already suggested a reduction in areas suitable for both species by 2050 and 2090, but we were able to point out the gradual loss that will occur throughout the century,” explains the researcher, who is currently a substitute professor in the Department of Biology and Zootechnics at the Faculty of Engineering (FEIS) at the Ilha Solteira campus of UNESP.

For example, in 2023, an article pointed out that areas expected to be lost by the southern muriqui would be in semi-deciduous forests (which lose part of their leaves during the dry season) in the interior of the states of Paraná and São Paulo. Vasconcelos reached similar conclusions in his current study, but adds that these areas will shrink even further, continuously, over the coming decades until the end of the century. There will also be a shift in the species’ range towards the northeast.

“This shift won’t occur with an increase in suitable areas, as is predicted to happen with some animal groups. On the contrary. With the significant loss of areas in the west of their current range, the remaining populations are likely to be restricted to the eastern part,” he explains.

Vasconcelos’s work indicates that the northern muriqui has experienced similar patterns of loss of climatically suitable areas over the decades, with an accelerated reduction expected between 2070 and 2090. Most of this species’ losses are expected to occur inland in the eastern and southern parts of Minas Gerais state, as well as central and western portions of Rio de Janeiro state. By 2090, São Paulo is expected to lose all climatically suitable areas for the species. By that year, only two large climatically suitable areas will remain for the northern muriqui. One will cover the northern population in the state of Bahia and northeastern Minas Gerais. The other will be in the state of Espírito Santo, with a smaller area in northern Rio de Janeiro.

The large climatically suitable areas that will concentrate most of the population by the end of the century are along the coast and associated with ombrophilous forests, a type of coastal or riparian vegetation that occurs in areas with high rainfall.

“Climate change is likely to pose particularly difficult challenges for populations of both species in inland areas associated with semi-deciduous forests.”

Solutions

The researcher emphasizes that the predictions only consider climate change, which could mask an even greater risk when considering synergistic threats, such as continuous habitat loss and forest fragmentation. Combined with the reduction of climatically suitable areas, this trend could lead to the isolation of muriqui populations and disrupt gene flow, which could affect the maintenance of viable populations. This could further reduce the species’ range. Local extinctions have already been documented in degraded areas of semi-deciduous forests.

Therefore, the author concludes the study by recommending a focus on conservation efforts for these populations and warning of the need for a better understanding of how they will respond to climate change in the coming decades.

In the medium and long term, the study emphasizes the importance of focusing efforts on protecting the two species of muriqui in coastal rainforests and identifying the best locations for ecological corridors to connect currently isolated populations.

“This would give the species the opportunity to maintain gene flow and persist as healthy populations in this century,” he concludes.

About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

Journal

Journal for Nature Conservation

DOI

10.1016/j.jnc.2025.127019

Article Title

Predicted losses over the 21st century in climatically suitable areas of threatened Muriquis (Primates, Brachyteles) in the Brazilian Atlantic Forest hotspot

African wildlife poop sheds light on what shapes the gut ecosystem

North Carolina State University

Nature calls for this gembok — image:
A study of elephants, giraffes and other wildlife in Namibia’s Etosha National Park underscores the ways in which the environment, biological sex, and anatomical distinctions can drive variation in the gut microbiomes across plant-eating species. Because the gut microbiome plays a critical role in animal health, the work can be used to inform conservation efforts. This photo shows a gembok in Etosha.
view more
Credit: James C. Beasley

A study of elephants, giraffes and other wildlife in Namibia’s Etosha National Park underscores the ways in which the environment, biological sex, and anatomical distinctions can drive variation in the gut microbiomes across plant-eating species. Because the gut microbiome plays a critical role in animal health, the work can be used to inform conservation efforts.

“This study is valuable because Etosha gave us the opportunity to sample such a large number of species under different environmental conditions,” says Erin McKenney, co-author of a paper on the work and an assistant professor of applied ecology at North Carolina State University. “That gives us meaningful insight into the role the environment plays in shaping the gut microbiome of herbivores.

“Unfortunately, this study may also be important for a second reason,” McKenney says. “Etosha is experiencing devastating wildfires affecting a huge section of the park. Because our samples were taken before the wildfires, these findings could inform recovery efforts by helping us understand how species’ microbiomes are adjusting to changes in diet that stem from the fire’s impact on the landscape.”

For this study, the researchers divided Etosha into three zones, depending on the amount of rainfall each zone received. The diversity and abundance of plant species varied from zone to zone, due to the precipitation differences, but nine of the 11 herbivore species were found in all three zones. The researchers were able to collect fresh feces samples from species ranging from African elephants (Loxodonta africana) and Angolan giraffes (Giraffa camelopardalis angolensis) to wildebeests, two species of zebra and a variety of antelope species.

The research team used DNA extraction and sequencing to identify what kinds of bacteria were present in the feces, which gave them information about the types and abundance of bacteria present in the gut microbiome of each animal.

“We ended up with 312 fecal samples across the 11 species, which gave us a wealth of microbiome data, and our analysis gave us a deeper understanding of the variables that can influence these microbial ecosystems,” says Rylee Jensen, first author of the paper and a recent master’s graduate from Northern Michigan University.

“One of the most interesting findings was that there were five types of bacteria that served as environmental indicators,” Jensen says. “Specifically, the relative abundance of these five microbes varied in a predictable way from zone to zone. All of these microbes are known for either breaking down lipids, breaking fiber down into nutrients animals can digest, or both. This is interesting because these environmental indicators could be key for helping us monitor environmental changes and how animal species are adapting to those changes.”

“Also, one of these environmental indicators is an entire phylum of bacteria that has previously been identified in the gut microbiome of camels,” McKenney says. “Camels are herbivores, but they are not closely related to any of the species we surveyed in this study, so to find that phylum here suggests it is a particularly robust indicator of environmental conditions in places where water is at a premium.”

The researchers also found a range of microbial differences that could be attributed to biological sex and gut morphology differences across species. However, there were some interesting findings involving the elephants.

“Elephants had two types of ‘core’ microbes – meaning these microbes were found in more than half of elephant samples – that were uncommon in the other species,” Jensen says. “This is likely due to the fact that elephants eat a wider variety of plant materials than the other species. This stood out because we found 22 types of core bacteria overall, and 20 of those types of bacteria were core bacteria for multiple species – but elephants hosted the only two types of core bacteria that were not common in other species. This highlights the role that feeding behavior and environment play on shaping the gut microbiome.”

“We’re excited about this work, in part, because we were able to collect high-quality samples from species in a region that had not previously been sampled for gut microbiome studies, and we got very fine resolution data,” says Diana Lafferty, co-author of the paper and an associate professor of biology at Northern Michigan.

“This is a level of detail and data quality that is often only achieved under captive or clinical conditions,” McKenney says.

“And we’ve essentially established a baseline that can be used to help us understand any changes we see in these species in this region,” Lafferty says. “That’s particularly important given the critical role that many of these species play in these ecosystems and the critical role gut microbiomes play in animal health.”

The paper, “Interspecific variation in gut microbiome diversity across the Etosha National Park herbivore community,” appears in the journal PLOS One. The paper was co-authored by Claudine Cloete, chief conservation scientist at Etosha Ecological Institute; James Beasley, the Terrell Distinguished Professor of Wildlife Management at the University of Georgia; and Madeline Melton, a Ph.D. student at UGA.

A study of elephants, giraffes and other wildlife in Namibia’s Etosha National Park underscores the ways in which the environment, biological sex, and anatomical distinctions can drive variation in the gut microbiomes across plant-eating species. Because the gut microbiome plays a critical role in animal health, the work can be used to inform conservation efforts. This photo shows an elephant and zebra in Etosha.