A new drug-delivery system could replace needles with puffs (股) of air. Gassensmith studies bioengineering at the University of Texas. His team’s new tech goes beyond patient comfort, though. The device quickly delivers drugs without touching the bloodstream. And that could reduce the risk of spreading disease. He tested it out on his own arm. “I could feel it, but it wasn’t painful,” he reports.

The technology works by blowing in a puff of air through the skin. That gas carries a powder made of tiny bits of vaccine (疫苗) wrapped in metallic crystals (晶体). The crystal coating is really strong, Gassensmith says. As a result, the vaccine powder does not have to be refrigerated while stored. The air contains carbon dioxide, or CO₂. Once in the body, the CO₂ that carries the powder will mix with water. It creates a weak acid that breaks down the crystal cover. Released, the vaccine bits are then able to enter the bloodstream.

This gas-based drug-delivery system is an upgrade over previous ones. For instance, adjusting the gas that carries the vaccine powder can customize how fast the tiny crystal capsules release the drug. Testing showed that the drug released fastest when delivered with carbon dioxide. Plain air led to a slower, gentler release. Vaccines work best when released slowly. That allows them longer contact with the immune(免疫) system. But the team hopes the device could work for other medicines too. And some medicines must be released quickly. One such example is insulin, a crucial drug for many people with diabetes.

Fear of needles keeps many people from getting vaccinations. Gassensmith is optimistic that this new system might get around that. Future research must ensure that gas-delivered vaccines build immunity to disease as expected, said Weniger, a doctor, who studied vaccine technology for 30 years for the U. S. Centers for Disease Control and Prevention.

Imagine a cat that does not need someone to clean up after it keeps an older people company and helps them remember to take their medicine. That is the shared dream of the toy maker Hasbro and scientists at Brown University in Providence, Rhode Island. The researchers received a $ 3-million-dollar from the National Science Foundation for a special project. They want to find ways to add artificial intelligence, or AI, to Hasbro’s “Joy for All” robotic cat.

The cat has already been for sale for two years. Though priced at over 1,000 dollars, it sold quite well. It was meant to act as a “companion”(陪伴) for older people. Now the project is aimed at developing additional abilities for the cat. Researchers are working to decide which activities older adults may need the most. They hope to make the cat perform a small number of activities very well. Such activities include finding lost objects and reminding the older people to take medicine or visit their doctor. They also want to keep the cost down to just a few hundred dollars.

It is an idea that has appealed (有吸引力) to Jeanne Elliott. Her 93-year-old mother Mary Derr lives with her in South Kingstown. Derr has dementia (痴呆). The Joy for All cat that Elliot bought this year has become a true companion for Derr. The cat stays with Derr and keeps her relaxed while Elliott is at work. Elliot said a robotic cat that helps her mother to remember to take her medicine and be careful when she walks would be greater.

The researchers are trying to learn how the improved cats will complete helpful activities and how they will communicate. They say that they do not want a talking cat, however. Instead they are trying to design a cat that can move its head in a special way to successfully communicate its message. In the end, they hope to create an exchange between the human and the cat in which the human feels the cat needs them. By doing so, the researchers hope they can even help prevent feelings of loneliness and sadness among elderly people.

Batteries can power anything from small sensors to large systems. While scientists are finding ways to make them smaller but even more powerful, problems can arise when these batteries are much larger and heavier than the devices themselves. University of Missouri(MU) researchers are developing a nuclear energy source that is smaller, lighter and more efficient.

“To provide enough power, we need certain methods with high energy density (密度)”，said Jae Kwon, assistant professor of electrical and computer engineering at MU. “The radioisotope (放射性同位素) battery can provide power density that is much higher than chemical batteries.”

Kwon and his research team have been working on building a small nuclear battery, presently the size and thickness of a penny, intended to power various micro/nanoelectromechanical systems (MNEMS). Although nuclear batteries can cause concerns, Kwon said they are safe.

“People hear the word ‘nuclear’ and think of something very dangerous,” he said, “However, nuclear power sources have already been safely powering a variety of devices, such as pace-makers, space satellites and underwater systems.”

His new idea is not only in the battery’s size, but also in its semiconductor(半导体). Kwon’s battery uses a liquid semiconductor rather than a solid semiconductor.

“The key part of using a radioactive battery is that when you harvest the energy, part of the radiation energy can damage the lattice structure(晶体结构) of the solid semiconductor,” Kwon said, “By using a liquid semiconductor, we believe we can minimize that problem.”

Together with J. David Robertson, chemistry professor and associate director of the MU Research Reactor, Kwon is working to build and test the battery, In the future, they hope to increase the battery’s power, shrink its size and try with various other materials. Kwon said that battery could be thinner than the thickness of human hair.