Today’s Deep Dive delves into one researcher’s quest to build a whiskered robot. But first, catch up on the latest science news, including birds that give a whole new meaning to ‘love is blind’ and bats with bird flu.
Animals | News from Science
Love is blind: Bird edition
The toupee-like feathers on the head of this male golden pheasant obscure his vision. Jiri Fejkl/Alamy
The unusual plumage of male golden and Lady Amherst’s pheasants helps them woo females, but it comes with a serious downside. The ornamentation renders the birds partially blind, researchers report in Biology Letters.
To make the find, scientists placed seven of the birds in a soft cradle. Then they used an ophthalmoscope (the same kind you’d see in a doctor’s office) to shine a light into the their eyes. The toupee of “love feathers” compromised the males’ binocular vision—especially their ability to look above them— by an average of 41% more than that of their female counterparts . For us, it would be a bit like sitting in the front row of a theater and trying to look up while wearing a baseball cap.
When the birds molt in September and October, their vision improves due to shedding of the cranial ornaments. In addition to being the first known case of sex-based vision difference in birds, the team says, the find represents the first known case of a bird’s visual field changing as the year progresses.
Vampire bats may have contracted H5N1 bird flu in Peru
In October 2022, migratory birds brought the avian influenza virus H5N1 to South America, where it soon ravaged both wild bird and marine mammal populations along the Pacific coast. Now, a study shows that the massive outbreak may have affected another mammal: common vampire bats that feed on the blood of marine animals. The study suggests H5N1—which is high on the list of potential pandemic agents—has an intriguing new route of transmission that could increase the risk of a pandemic.
Bats live in dense groups, making it easier for viruses to pass from one animal to the other; they could become a permanent new reservoir for H5N1 more easily than other mammalian species. And because some of Peru’s vampire bats dine on livestock, they could form a bridge that carries the virus from marine to terrestrial mammals, the researchers say.
But, as scary as H5N1-infected vampire bats may sound, influenza scientists aren’t alarmed just yet, because the virus did not spread between bats, a prerequisite for them becoming a viral reservoir. “Anytime we find H5N1 in a different species, or a different route of infection, that increases the [pandemic] risk. But in itself, this is not something that we should get too worried about,” explained flu virologist Richard Webby. Still, “It’s a very cool paper,” Webby said.
Technology and climate resilience: Protecting health in the Amazon
As climate change transforms the Amazon, communities face new threats—from water scarcity to rising infectious disease. In this Science Webinar, experts discuss innovations to safeguard health in one of the world’s most climate-vulnerable regions.
This object-identifying robot is the cat’s whiskers (no, like, literally). Ricardo Cortez
Robot with catlike whiskers identifies objects by touch
Phie Jacobs, General Assignment Reporter, News from Science
Whiskers may make cats extra adorable, but they’re not just for show. These specialized hairs sense detailed information when they brush against objects, helping our fuzzy friends evaluate their position in space, navigate their environment, and expertly knock things off dressers in the middle of the night.
This iconic feline trait gave Ricardo Cortez, a bionic engineer at the National Polytechnic Institute in Mexico City, the idea for a robotic sensing system that—like a cat’s whiskers—detects and identifies nearby objects by colliding with them. He drew inspiration from his own cat, who served as the “first participant” for a study describing the work, published last month in the journal Processes.
Cortez and his students began the project by collecting test subjects’ whiskers and examining them under a microscope. This task required some patience, Cortez notes, since cats only shed their whiskers every few months, usually losing only one or two at a time. The analysis revealed that a whisker’s inner and outer sections are composed of slightly different materials, influencing the way it reacts when it hits something. To replicate this, the team gave their artificial whiskers a core of soft silicon and an exterior of semi-flexible 3D printing resin. This latter material, Cortez says, is similar to the stiff keratin that composes real cat whiskers.
To figure out how these phony whiskers should move, the team also collected extensive video footage of cats as the animals reacted to audio recordings of mewling kittens, devoured wet food, sniffed catnip, and interacted with a variety of toys and other objects. And while real cat whiskers are connected to multiple sensitive nerve endings that pick up on every slight movement and vibration when the whisker collides with an object, the robotic system relies on a software algorithm known as an extended state observer (ESO) to estimate the size of the disturbance.
ScienceAdviser sat down with Cortez to learn more about the project. The interview has been edited for length and clarity.
It seems like this project involved a lot of playing with cats. What was that like?
There were several challenges. First, we needed to restrict the number of people that were present during the experiment. We also needed to eliminate any odor or sign of other cats. But once we had video footage of all the cats, we could use image processing to determine the range of motion of their whiskers. We found that whiskers are capable of two types of motion, translational and rotational, so we created a robotic system actuated with motors that can do both.
Cortez’s cat Atenea served as the inspiration for the work. Ricardo Cortez
How did you actually build the robot?
We tried several different combinations of materials for the artificial whiskers. The whisker needs to be flexible, but if it’s too soft, then vibrations will be dampened by the time they reach the motor shaft. And if the whisker is too rigid, it will break when it collides with an object.
Cat whiskers themselves don’t have any nerve endings. They’re just made of keratin, like hair. But there are nerve endings in the cat’s skin that detect when the whiskers move. We tried to emulate this with a tool called an extended state observer or ESO, which was developed by researchers in the field of automatic control to estimate and counteract disturbances on control strategies.
How does an ESO work?
In every robotic system, you have the input, the output, and all the external disturbances that affect the behavior of the system. If the artificial whisker moves but doesn’t make contact with anything, then the disturbance affecting its motor is very small. But when the whisker collides with an object, that perturbation changes, and you can capture information about it with the ESO. A rigid material, like metal or wood, creates vibrations that perturb the motor in a different way than a soft material—like foam, rubber, or sponge—does.
So what does this robot look like in action?
The robotic system has a routine: Move forward, rotate whiskers, and return. This process takes around five to ten seconds, and then we obtain the data, estimate the perturbation, and analyze the frequency of the vibrations. Once we get that, we use a machine-learning model to differentiate between hard and soft materials. In this paper, our algorithm accurately classified about 70% of samples.
What could this type of robotic system be used for?
It could be useful in cases where visibility is very low and a traditional camera just doesn’t work. You could use an expensive infrared camera or an ultrasonic sensor to get a 360-degree view of a room, but that still wouldn’t tell you the characteristics of objects in that room. Our robot, by contrast, could determine what material an object is made of without taking a physical sample, which can be invasive or destructive.
What’s next for this line of research?
This current system is a prototype that could be improved. As you can see, it only has two whiskers, while cats have many, many whiskers. I’m already excited to continue this work, because the first thing we need to improve is the sample size. That means more cats, and more time with the cats.
Whole-genome sequencing of over 100 cells from a 74-year-old man has revealed just how much our genomes differ throughout the body. “There were some cells in there that were very messed up,” one of the researchers said—not just mutations but chunks of chromosomes cut and pasted onto others, and some cells were even lacking their Y chromosome altogether. The findings and future similar studies will help scientists tease out harmless changes from ones that underlie disease.
Our bodies constantly monitor what’s happening inside us—but researchers aren’t entirely sure how that intel is relayed to our brains. This sense of our insides, called interoception, is the focus of a new $14.2 million NIH award. “Just in the last five years, fundamental puzzles that have been around for 100 years have been solved,” one expert noted—and it’s hoped the new effort will accelerate discoveries even more.
Dark matter is so named because astronomers can’t see it directly. But they may have caught a glimpse: gamma radiation from part of the Milky Way. By one scientist’s calculations, the gamma glow is 20 gigaelectron volts greater than it should be, possibly the glimmer of WIMPs, the prime particle candidate for dark matter, self-annihilating (as WIMPs are wont to do). “Even though the research began with the aim of detecting dark matter signals, I thought it was like playing the lottery. So, when I first spotted what seemed like a signal, I was skeptical,” the researcher said. “But when I took the time to check it meticulously and felt confident it was correct, I got goosebumps.” Though others aren’t convinced.
We are entering a post-transition world in which the tools and theories that served demography so well are under strain—especially when it comes to anticipating future fertility.
Tomorrow, I’ll be kicking back and relaxing, musing on all the things I’m truly grateful for. And I just so happen to have a nice bottle of port to sip on while I do—what excellent timing to have read this lovely deep dive on the chemistry of this tasty wine.
Christie Wilcox, Editor, ScienceAdviser
With contributions from David Grimm and Martin Enserink
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