How tiny drones inspired by bats could save lives in dark and stormy conditions

WORCESTER, Mass. (AP) — Don't be fooled by the fog machine, spooky lights and fake bats: the robotics lab at Worcester Polytechnic Institute lab isn't hosting a Halloween party.

Instead, it’s a testing ground for tiny drones that can be deployed in search and rescue missions even in dark, smoky or stormy conditions.

“We all know that when there’s an earthquake or a tsunami, the first thing that goes down is power lines. A lot of times, it’s at night, and you’re not going to wait until the next morning to go and rescue survivors,” said Nitin Sanket, assistant professor of robotics engineering. “So we started looking at nature. Is there a creature in the world which can actually do this?”

Sanket and his students found their answer in bats and the winged mammal's highly sophisticated ability to echolocate, or navigate via reflected sound. With a National Science Foundation grant, they’re developing small, inexpensive and energy-efficient aerial robots that can be flown where and when current drones can’t operate.

Last month, emergency workers in Pakistan used drones to find people stranded on rooftops by massive floods. In August, a rescue team used a drone to find a California man who got trapped for two days behind a waterfall. And in July, drones helped find a stable route to three mine workers who spent more than 60 hours trapped underground in Canada.

But while drones are becoming more common in search and rescue, Sanket and researchers elsewhere want to move beyond the manually operated individual robots being used today. A key next step is developing aerial robots that can be deployed in swarms and make their own decisions about where to search, said Ryan Williams, an associate professor at Virginia Tech.

“That type of deployment — autonomous drones — that is effectively nil,” he said.

Williams tackled that problem with a recent project that involved programming drones to choose search trajectories in coordination with human searchers. Among other things, his team used historical data from thousands of missing person cases to create a model predicting how someone would behave if lost in the woods.

“And then we used that model to better localize our drones, to search in locations with higher chances of finding someone,” he said.

At WPI, Sanket’s project addresses other limitations of current drones, including their size and perception capabilities.

“Current robots are big, bulky, expensive and cannot work in all sorts of scenarios,” he said.

By contrast, his drone fits in the palm of his hand, is made mostly from inexpensive hobby-grade materials and can operate in the dark. A small ultrasonic sensor, not unlike those used in automatic faucets in public restrooms, mimics bat behavior, sending out a pulse of high-frequency sound and using the echo to detect obstacles in its path.

During a recent demonstration, a student used a remote control to launch the drone in a brightly lit room and then again after turning off all but a faintly glowing red light. As it approached a clear, Plexiglas wall, the drone repeatedly halted and backed away, even with the lights off and with fog and fake snow swirling through the air.

“Currently, search and rescue robots are mainly operational in broad daylight,” Sanket said. “The problem is that search and rescues are dull, dangerous and dirty jobs that happen a lot of times in darkness.”

But development didn’t go completely smoothly. The researchers realized that the noise of the bat robot’s propellers interfered with the ultrasound, requiring 3D printed shells to minimize the interference. They also used artificial intelligence to teach the drone how to filter and interpret sound signals.

Still, there’s a long way to go to match bats, which can contract and compress their muscles to listen only to certain echoes and can detect something as small as a human hair from several meters away.

“Bats are amazing,” Sanket said. “We are nowhere close to what nature has achieved. But the goal is that one day in the future, we will be there and these will be useful for deployment in the wild.”

Robotics engineering students change out the battery on a tiny drone at a laboratory at Worcester Polytechnic Institute, Monday, Oct. 20, 2025, in Worcester, Mass. (AP Photo/Charles Krupa)

Nitan Sanket, assistant professor of robotics engineering, describes the components on a tiny drone at his lab at Worcester Polytechnic Institute, Monday, Oct. 20, 2025, in Worcester, Mass. (AP Photo/Charles Krupa)

Colin Balfour, a sophomore studying robotics engineering, flies a small drone at a laboratory at the Worcester Polytechnic Institute, Monday, Oct. 20, 2025, in Worcester, Mass. (AP Photo/Charles Krupa)

A tiny drone flies through a simulated snowstorm at night at a laboratory at Worcester Polytechnic Institute, Monday, Oct. 20, 2025, in Worcester, Mass. (AP Photo/Charles Krupa)

Colin Balfour, a sophomore studying robotics engineering, right, flies a small drone through a simulated snowstorm at night at a laboratory at the Worcester Polytechnic Institute, Monday, Oct. 20, 2025, in Worcester, Mass. (AP Photo/Charles Krupa)

Colin Balfour, a sophomore studying robotics engineering, checks the rotors on a small drone at a laboratory at the Worcester Polytechnic Institute, Monday, Oct. 20, 2025, in Worcester, Mass. (AP Photo/Charles Krupa)

Colin Balfour, a sophomore studying robotics engineering, flies a small drone at a simulated night flight at a laboratory at the Worcester Polytechnic Institute, Monday, Oct. 20, 2025, in Worcester, Mass. (AP Photo/Charles Krupa)

FILE - A vampire bat is caught in a net in Aracy, in the northeast Amazon state of Para, Brazil, on Thursday, Dec. 1, 2005. (AP Photo/Mario Quadros, File)

SEOUL, South Korea (AP) — Chang Ung, a former North Korean member of the International Olympic Committee who once led sports exchanges with rival South Korea, including joint marches of their athletes at the Olympics, has died, the IOC announced Wednesday. He was 87.

The IOC said on its website that it had learned with “extreme sadness” of Chang’s death on Sunday. It said the Olympic flag will be flown at half-mast for three days at the Olympic House in Lausanne, Switzerland.

The IOC statement didn't describe the cause of Chang's death. North Korea’s state media has not reported on his death.

Born in 1938, Chang was originally a basketball player who captained the North Korean national team. After retiring from the sport, he became an athletics administrator, serving as a vice sports minister, a vice chairman of North Korea’s national Olympic Committee and a vice president of the Olympic Council of Asia.

In 1996, Chang was elected to the IOC. As North Korea’s only-ever IOC member, he represented his country on international sports fields and headed numerous — if often rocky — talks with South Korea to promote sports exchange and cooperation programs between the rivals.

The most notable results of this diplomacy came at the 2000 Sydney Olympics, when athletes of the two Koreas marched together under a “unification flag” depicting their peninsula during the opening and closing ceremonies, the first joint parade since their division in 1945.

Athletes of the Koreas walked together at following Olympic Games and major international sports events, including the 2018 Pyeongchang Olympics in South Korea. After watching a joint march in Pyeongchang’s opening ceremony, Chang told reporters that he was deeply moved.

Chang played a key role in earlier reconciliation talks with South Korea, which led to the two countries sending their first unified male and female teams to the 1991 world table tennis championships in Chiba, Japan. In Pyeongchang, the two Koreas fielded their first combined Olympic team for women’s ice hockey.

In a 2004 interview with South Korea’s Chosun Ilbo newspaper, Chang said that organizing the 2000 joint march was “really a tough” job. He also said he strongly supported Pyeongchang’s earlier, failed bid to host the Winter Olympics.

South Korean Unification Minister Chung Dong-young expressed condolences over Chang’s death. In a Facebook post Wednesday, Chung, a staunch advocate of rapprochement with North Korea, recalled his 2007 meeting with Chang on taekwondo exchange programs and said he honors Chang's “noble dedication to (Korean) unity and peace.”

Sports ties between North and South Korea have suffered as political relations frayed.

There have been no sports or other exchange programs between the countries for years. North Korea has shunned talks with South Korea and the U.S. since its leader Kim Jong Un’s broader nuclear diplomacy with U.S. President Donald Trump collapsed in 2019. Kim also branded South Korea as a permanent enemy and rejected the idea of future unification.

The IOC said Chang’s contributions helped advance sports participation, cultural exchanges and the role of sport in society.

“His efforts to promote cooperation on the Korean Peninsula demonstrated the power of sport to build bridges and inspire hope,” IOC President Kirsty Coventry said.

The IOC said Chang served on several commissions, including Sport for All and the International Olympic Truce Foundation.

North Korea’s official news agency, KCNA, last mentioned Chang in 2023, when he was awarded the Olympic Order, an award given to those who have made extraordinary contributions to the Olympics, during an IOC session in Mumbai, India. Chang, then an honorary IOC member, joined the ceremony by video.

FILE - Then North Korea's International Olympic Committee, IOC, member Chang Ung, middle row left, waves with officials of International Taekwondo Federation for the media upon their arrival at Gimpo International Airport in Seoul, South Korea, on June 23, 2017. (AP Photo/Lee Jin-man, File)

FILE - Then North Korea's IOC representative Chang Ung, left, arrives after a flight from Pyongyang at Beijing Capital International Airport in Beijing, on Jan. 16, 2018. (AP Photo/Mark Schiefelbein, File)

FILE - Then North Korea's IOC representative Chang Ung arrives after a flight from Pyongyang at Beijing Capital International Airport in Beijing on Jan. 16, 2018. (AP Photo/Mark Schiefelbein, File)