Inventors have dreamed up masks with motorized air purifiers, Bluetooth speakers and even sanitizers that kill germs by heating the face covering (but hopefully not the face) to over 200 degrees. In South Korea, the electronics giant LG has created a mask powered with fans that make it easier to breathe.

In boutiques, patterned masks are showing up on mannequins, exquisitely paired with designer dresses. An Indian businessman said he spent $4,000 on a custom mask made of gold. And a French costume designer has filled Instagram with phantasmagoric designs featuring everything from pterodactyls to doll legs.

The coronavirus “has driven a rapid evolution in mask technology,” said Yukiko Iida, an expert on masks at the Environmental Control Center, a consulting company in Tokyo.

“When there’s demand, the market reacts quickly,” she said. “People are wearing them all day every day, so we’re seeing improvements in things like ease of wear and ease of communication,” she added, citing a mask with a clear front that allows people to see the wearer’s facial expressions.

The urge to innovate has been great in Japan, where masks were widespread even before the pandemic, used to warm faces or protect against pollen, influenza or the unwelcome gaze of strangers.

While most people in the country are still wearing cheap white surgical masks, consumers have begun to move away from viewing face coverings as a one-and-done commodity, something picked up at a convenience store, worn a few times and tossed in the trash.

His company is building a mask that serves as a combination walkie-talkie, personal secretary and translator. It can record its users’ voice, projecting it to someone else’s smartphone — all the better for social distancing — or transmuting it from Japanese into a variety of languages.

“The pandemic made this possible,” he said, noting that his prototype had generated media attention and enormous interest from investors on Makuake, a Japanese version of Kickstarter. Before, he said, “even if you made something like this, no one would invest in it, and you couldn’t sell it. Now, the global market has grown several times.”

While it’s unclear how well some of these more ambitious masks will fare with consumers, one innovation has been a clear hit: face coverings with high-tech fabrics that are said to provide superior comfort or protection.

As summer temperatures rise, masks made of materials intended to keep wearers cool are in demand. People who have been wearing reusable cloth masks — including those sent by the Japanese government to every household in the country — are finding them ill suited for the heat and humidity of summer in central Japan, much less Singapore or Hong Kong.

Toyoshima, a Nagoya-based trading company, began collecting funds for a new mask made with military-grade nylon in mid-April. It raised over $1.2 million — more than 13,000 percent of its goal.

Customers told the company that they wanted a highly effective mask that was also fashionable, said Koki Yamagata, who leads the company’s crowdfunding initiatives.

Other Japanese companies have followed suit. Tadashi Yanai, the founder of Uniqlo, the giant clothing retailer, insisted that his company would not sell masks, but changed his mind after customers clamored for a product made from the brand’s high-performance, fast-drying fabric.

The masks sold out immediately, and the company has committed to making 500,000 packs a week, according to a spokesman, Aldo Liguori, who said that the company was now planning to sell them overseas, as well.

Many “factories haven’t had much to do for two or three months, so they’re saying ‘Why don’t we make cloth masks?’” said Kensuke Kojima, a product consultant for the fashion industry.

These Japanese producers have entered a market that had seen only incremental changes over the decades, like masks that came in different colors or offered no-smear coatings to protect makeup.

They were first employed to fight epidemics in the early 20th century, when Wu Lien-teh, a doctor of Chinese descent, began promoting simple gauze masks as an effective method for battling an outbreak of pneumonic plague in a part of northeastern China then known as Manchuria.

When the Spanish flu hit in 1918, the practice went global for the first time.

While masks soon fell out of favor in most countries, the Japanese government continued encouraging their use for fighting common illnesses like the flu, said Christos Lynteris, a medical anthropologist at the University of St. Andrews in Scotland.

The ubiquity of surgical masks in Japan, which are typically made of nonwoven synthetic materials, has risen and fallen over the years as the country confronted different health issues and crises.

In the 1990s, they became a popular defense against clouds of seasonal pollen created by fast-growing trees, like cypress, planted across the country to provide a source of cheap timber.

In 2011, after the nuclear meltdown at Fukushima, mask stocks ran low as consumers feared radioactive fallout. And in the following years, drastic increases in pollution from China drove more demand, particularly in the winter.

But, even in Japan, it took a pandemic to push mask sales into the stratosphere, with face coverings in such short supply early on that people were lining up at the crack of dawn to buy a box.

Months later, masks are abundant, and shops in Harajuku, the youth fashion mecca, are increasingly putting them on prominent display. On Takeshita Street, storefronts are lined with masks ranging from the playful (plush animal faces) to the punk-inspired (leather straps studded with spikes and safety pins).

Although these masks may be fashionable, buyers should beware, said Kazunari Onishi, an expert on infectious diseases at the Graduate School of Public Health at St. Luke’s International University in Tokyo.

“You must choose a mask that meets the national standards,” he said, adding that “other types of masks are not intended to be used against infection.”

“If your priority is reliably preventing infection, these masks will not protect your life,” he said, adding that even if you wear a mask, “you must maintain safe social distancing.”