Today we continue with our series on IEEE/RSJ IROS 2020 (International Conference on Intelligent Robots and Systems) original series Real Roboticist. This time you’ll meet Radhika Nagpal, who is a Fred Kavli Professor of Computer Science at the Wyss Institute for Biologically Inspired Engineering from Harvard University.
Did you know Rhadika directed the research that led to the creation of the Kilobots, the first open-source, low-cost robots that were specifically designed for large scale experiments with hundreds and thousands of them? You can watch this example or this other one if you’re curious. If you’d like to know more about Rhadika and her achievements, challenges and what she would tell her younger self, below is the whole interview. Enjoy!
Segmented hinges in the long, thin bones of fish fins are critical to the incredible mechanical properties of fins, and this design could inspire improved underwater propulsion systems, new robotic materials and even new aircraft designs.
The thin lines in the tail of this red snapper are rays that allow the fish to control the shape and stiffness of its fins. Francois Barthelat, CC BY-ND
Fish fins are not simple membranes that fish flap right and left for propulsion. They probably represent one of the most elegant ways to interact with water. Fins are flexible enough to morph into a wide variety of shapes, yet they are stiff enough to push water without collapsing.
The secret is in the structure: Most fish have rays – long, bony spikes that stiffen the thin membranes of collagen that make up their fins. Each of these rays is made of two stiff rows of small bone segments surrounding a softer inner layer. Biologists have long known that fish can change the shape of their fins using muscles and tendons that push or pull on the base of each ray, but very little research has been done looking specifically at the mechanical benefits of the segmented structure.
A pufferfish uses its small but efficient fins to swim against, and maneuver in, a strong current.
To study the mechanical properties of segmented rays, my colleagues and I used theoretical models and 3D-printed fins to compare segmented rays with rays made of a non-segmented flexible material.
We showed that the numerous small, bony segments act as hinge points, making it easy to flex the two bony rows in the ray side to side. This flexibility allows the muscles and tendons at the base of rays to morph a fin using minimal amounts of force. Meanwhile, the hinge design makes it hard to deform the ray along its length. This prevents fins from collapsing when they are subjected to the pressure of water during swimming. In our 3D-printed rays, the segmented designs were four times easier to morph than continuous designs while maintaining the same stiffness.
The segmented nature of fish fin rays allows them to be easily morphed by pulling at the bottom of the ray. Francois Barthelat, CC BY-ND
Why it matters
Morphing materials – materials whose shape can be changed – come in two varieties. Some are very flexible – like hydrogels – but these materials collapse easily when you subject them to external forces. Morphing materials can also be very stiff – like some aerospace composites – but it takes a lot of force to make small changes in their shape.
It requires much more force to control the shape of a continuous 3D-printed ray (top two images) than to morph a segmented ray (bottom two images). Francois Barthelat, CC BY-ND
The segmented structure design of fish fins overcomes this functional trade-off by being highly flexible as well as strong. Materials based on this design could be used in underwater propulsion and improve the agility and speed of fish-inspired submarines. They could also be incredibly valuable in soft robotics and allow tools to change into a wide variety of shapes while still being able to grasp objects with a lot of force. Segmented ray designs could even benefit the aerospace field. Morphing wings that could radically change their geometry, yet carry large aerodynamic forces, could revolutionize the way aircraft take off, maneuver and land.
What still isn’t known
While this research goes a long way in explaining how fish fins work, the mechanics at play when fish fins are bent far from their normal positions are still a bit of a mystery. Collagen tends to get stiffer the more deformed it gets, and my colleagues and I suspect that this stiffening response – together with how collagen fibers are oriented within fish fins – improves the mechanical performance of the fins when they are highly deformed.
What’s next
I am fascinated by the biomechanics of natural fish fins, but my ultimate goal is to develop new materials and devices that are inspired by their mechanical properties. My colleagues and I are currently developing proof-of-concept materials that we hope will convince a broader range of engineers in academia and the private sector that fish fin-inspired designs can provide improved performance for a variety of applications.
Francois Barthelat does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Automated packaging solutions can streamline almost any business’s operations, providing a potential competitive edge and benefits like reduced waste or lower labor needs.
After dominating the electric vehicle market and throwing his hat into the billionaire space race, Tesla boss Elon Musk announced the latest frontier he's aiming to conquer: humanoid robots.
At a Tokyo cafe, Michio Imai greets a customer, but not in person. He's hundreds of kilometres away, operating a robot waiter as part of an experiment in inclusive employment.
You find a new restaurant with terrific food, but when you suggest meeting there in a group text to your friends, the choice to meet at the same old place carries the day.
Up until now, users in the metal and plastics processing industries often faced a difficult choice: with CNC lathes and milling machines, one opted either for the largest possible variance or for large volumes, i.e., high quantities.
A team of engineers and physicians has developed a steerable catheter that for the first time will give neurosurgeons the ability to steer the device in any direction they want while navigating the brain's arteries and blood vessels. The device was inspired by nature, specifically insect legs and flagella—tail-like structures that allow microscopic organisms such as bacteria to swim.
For people with amputation who have prosthetic limbs, one of the greatest challenges is controlling the prosthesis so that it moves the same way a natural limb would. Most prosthetic limbs are controlled using electromyography, a way of recording electrical activity from the muscles, but this approach provides only limited control of the prosthesis.
Topical Area: Driverless Vehicles and Field Robots
Bio: Dr. Anna Petrovskaya is a scientist and entrepreneur with decades of experience in the field of AI, autonomy, and 3D computer vision. Most recently, Anna built a 3D mapping startup that was acquired by Mobileye/Intel, where she became Head of LiDAR AI. She completed her Doctorate degree in Computer Science at Stanford University in 2011, where she focused on Artificial Intelligence and Robotics. In 2012, her thesis was named among the winners of the IEEE Intelligent Transportation Systems Society Best PhD Thesis Award. Anna was part of the core team that built the Stanford autonomous car Junior, which was a precursor to the Waymo/Google autonomous car. She has served as an Associate Editor for International Conference on Robotics and Automation (ICRA) since 2011. Based on her expertise, Anna has been invited to co-author chapters for the Handbook of Intelligent Vehicles and the 2nd edition of the Handbook of Robotics
Prof. I-Ming Chen – Automation of Food Handling: From Item-Picking to Food-Picking
Topical Area: Food Handling Robotics
Bio: I-Ming Chen received the B.S. degree from National Taiwan University in 1986, and M.S. and Ph.D. degrees from California Institute of Technology, Pasadena, CA in 1989 and 1994 respectively. He is currently Professor in the School of Mechanical and Aerospace Engineering of Nanyang Technological University (NTU) in Singapore, and Editor-in-chief of IEEE/ASME Transactions on Mechatronics. He is Director of Robotics Research Centre in NTU from 2013 to 2017, and is also a member of the Robotics Task Force 2014 under the National Research Foundation which is responsible for Singapore’s strategic R&D plan in future robotics. Professor Chen is Fellow of Singapore Academy of Engineering, Fellow of IEEE and Fellow of ASME, General Chairman of 2017 IEEE International Conference on Robotics and Automation (ICRA 2017) in Singapore. His research interests are in logistics and construction robots, wearable devices, human-robot interaction and industrial automation. He is also CEO of Transforma Robotics Pte Ltd developing robots for construction industry and CTO of Hand Plus Robotics Pte Ltd developing robotics and AI solutions for logistics and manufacturing industry.
In the last few years, delivery robots and drones have popped up around the U.S., occasionally rolling, walking or flying up to people's doorsteps to drop off packages. But one consideration that needs to be addressed before widely adopting autonomous technologies is their environmental impact. Now, researchers reporting in ACS' Environmental Science & Technology show that automating residential package transport doesn't influence the greenhouse gas footprint as much as the delivery van's size and type.
Sea cucumbers have a bumpy and oblong shape. They are soft but stiffen up quickly when touched. They can shrink or stretch to several meters, and their original shape can be recovered even after they die and shrivel up with the regulation of water uptake. Recently, a POSTECH research team has developed a soft actuator inspired by this unique behavior of sea cucumbers.
Most robots use servo motors to move their joints, calling for rotary or angle encoders. As speeds increase, so do the control dynamics the motors require, sometimes making vibration mitigation just as important accuracy and resolution.
If automation was as simple as getting a loan, buying the system, and making more money, every business in the country would be automated. Unfortunately, there are some large roadblocks standing between small businesses and complete optimization of their production lines.
