January 11, 2024: I'm filling in for Andrea Gawrylewski for the next few days. Below, learn about the first-ever biorobotic heart, the largest known ape species, and public trust in driverless cars. —Robin Lloyd, Contributing Editor | | | A new approach to building robots relies on feedback-based algorithms to arrange joints and artificial muscles in a simulated brick of a gelatinous substance. It ultimately yielded a physical bot that could travel half its body length each second. By repeating an algorithmic process as few as 100 times on a digital brick with 64 holes randomly interspersed throughout and 64 randomly placed artificial muscle patches, the researchers optimized various robots for such functions as speed, carrying or throwing. The team cast one of the designs in silicone, reports science writer Matthew Hutson, yielding a physical creature about half the size of a bar of soap. Pulses of air pumped into tiny bladders affixed to the hopping robot gave it muscle. The entire design process for the speedy bot took just 30 seconds on a laptop. Using human engineers, the same process could take months or years. How they did it: Movement-maximizing adjustments were guided by a type of optimization algorithm that finds solutions to problems with an unwieldy number of variables. In this case, the variables were muscle locations, as well as hole locations and sizes.
What the experts say: The approach could "help usher in the world of bespoke robotics," says computer scientist Josh Bongard of the University of Vermont, co-author of a study detailing the design approach. | | | The health risks of obesity haven't changed. However, a recent study showed just how imprecisely body mass index (BMI) can diagnose the condition and measure overall health, reports science journalist Lydia Denworth. BMI is calculated by dividing an individual's weight in kilograms by the square of their height in meters. An analysis of data on about 3,000 Israeli men and women revealed that roughly one third of those whose BMI placed them in the normal range were found to be obese when their actual body fat was measured. And a third of those identified as overweight by their BMI had normal amounts of body fat. The problem: A decade ago, the American Medical Association recognized obesity as a disease and linked it to cancer, diabetes, heart disease and other dangerous conditions. That thinking still holds up. However, BMI fails to distinguish between muscle and fat, as well as where that tissue is located in the body. And with fat, location matters. Also, BMI is based on height and weight tables developed using data from non-Hispanic white people, mostly men. But race, ethnicity, sex and age affect body composition and health risks differently.
The solutions: To better assess health, doctors and other health care providers should combine BMI with measures such as waist circumference and blood pressure, one expert says. Another approach is to use bioelectrical impedance analysis, which uses electric signals to distinguish fat from muscle in the body. | | | • A first-ever biorobotic heart, made from living tissue fused with robotic muscles, could help scientists see how the organ works on the inside. | 3 min read | | | • The U.S. needs smarter regulations for driverless vehicles, writes Steven E. Shladover, an engineer who studies applications of advanced technologies for transportation systems. Otherwise, it will be difficult for automated driving technology to realize its safety-enhancing potential and thus for the industry to earn public trust in the safety of driverless vehicles. In the near term, automated driving system developers and fleet operators should be required to report all crashes, near misses, high-g maneuvers and human control takeovers. Also, developers and operators should ensure that systems cannot operate where behavior has not been shown to be safe. | 4 min read | | | The item above about algorithms, simulated gelatinous bricks and silicone casts of hopping robots brought to mind earlier days playing Dungeons & Dragons. My dad was a devious Dungeon Master. He occasionally challenged us with an adversary whose name we loved to repeat: a gelatinous cube. I suppose many dungeon masters over the years have favored dragons to defeat players. Certainly dragons are having their day in recent decades thanks in part to The Lord of the Rings and Game of Thrones series on screens large and small. For more dragon daydreaming, check out this essay about the ubiquity of dragons across human cultures, by writer Kelly Reidy. The biographical sketch states that Reidy has led offbeat museum tours and performed ukulele songs about love and mathematics. | If you have any feedback, suggestions, or spot any errors while reading these newsletters, please reach out to us. | —Robin Lloyd, Contributing Editor | Subscribe to this and all of our newsletters . | | | Scientific American One New York Plaza, New York, NY, 10004 | | | | Support our mission, subscribe to Scientific American | | | | | | | | |