Trick or treat! With Halloween around the corner, kids are about to collect bags full of candy, including chocolate. Meanwhile, a group of researchers in the Netherlands has been experimenting with a method to make chocolate more of a “treat” than ever.

While chocolate is delicious for many reasons, this study focused on how it cracks when it is bitten. Corentin Coulais, the researcher teaching physics at the University of Amsterdam says, “To better how it feels in the mouth, we gave ‘geometry (几何学)’ to chocolate, which would then change the way it breaks.”

Giving it “geometry” involved using a 3D printer to produce dark chocolate in various ways. Rather than creating a flat, solid piece, the machine printed it into a simple S-shape, or zigzagged super-thin layers back-and-forth several times, or into increasingly complicated spirals (螺旋形). The resulting pieces were fed to 10 eager volunteers. It turned out that the crunchiest (最松脆的)—while remaining easy to bite—was the chocolate shaped into fairly complicated spirals. It was also the top tasting experience.

The researchers also used a machine to crack the various shapes and see which was the crunchiest. Plus, they recorded the sounds of the cracking, because a pleasurable eating experience doesn’t only take place in the mouth, but can be affected by the noises in your head. The general winner remained that spiral.

“It’s too early to say whether chocolate will soon be made differently,” Coulais says.

He is working with a couple of organizations to see how it might be applied in materials other than chocolate—ones that might be used in vehicles, for example, to make them less dangerous when they crash.

Understanding cracking could make life safer—in cars or airplanes or wearing helmets. It could also make those Halloween treats even tastier.

Time magazine listed its top inventions of 2019, some of which will surely become a big part of our everyday lives over the next decade. Here are some we're most looking forward to.

●Virtual （虚拟的）surgery

According to Harvard Business Review, our current system of training surgeons can't keep up with the speed of technological development. “Even after 4 years of college, 4 years of medical school and 5 years of advanced training after working, 30% of graduates still can't operate on their own,” said Justin Barad, who is the CEO and co-founder of Osso VR.

This VR software is made to give doctors virtual operating-room experience so they can practice and prepare for surgeries. Apparently, it works. Gideon Blumstein of California University conducted a study on using Osso VR. His team found that participants' overall surgical performance improved by an astonishing 230% over traditional training methods.

● Vending veggies （出售素食）

"Eat happier. ” That's the Farmers Fridge advertising message. It is a good one, as this company wants to bring fresh, healthy food to people on the go.

It's trying to change more than just food, though. It also wants to change the delivery method. Farmers Fridge has created its very own automatic machines. They can be placed in high-traffic areas. These super-smart vending machines can know their contents at any moment, and can allow customers to reserve and pay in advance. They can even learn about what customers want. Shayna Harris is the company's Chief Growth Officer. “We have developed salads, sandwiches and breakfast items that taste as fresh as if you were to make them in your home kitchen,” she said in an interview with Insider Trends.

● Recycling pollution

When we write with black ink, we're writing with soot — a powder made by burning coal or oil. Cars are machines that produce soot. To collect the soot, Anirudh Sharma, creator of AIR-INK, made a device called Kaalink, which attaches to a vehicle’s exhaust pipe （排气管）.Once collected, it's made into ink color and mixed with vegetable oil to create inks, markers and paints with the brand AIR-INK.

“I don't know if it's pollution, but the quality of the ink is really special,” said artist Kristopher Ho. “It's black, really thick and dries extremely quickly.”

The Guardian describes AIR-INK as "remarkably green”. Each 30-milliliter pen contains between 40—50 minutes of air pollution, while each 6-liter spray can hold 2,000 minutes of diesel exhaust （柴油废气）. In the past year, Sharma said, his team has cleaned nearly 1.7 trillion （万亿）liters of air in India and Hong Kong.

Whether in the home or the workplace, social robots are going to become a lot more common in the next few years. Social robots are about to bring technology to the everyday world in a more humanized way, said Cynthia Breazeal, chief scientist at the robot company Jibo.

While household robots today do the normal housework, social robots will be much mow like companions than mere tools. For example, these robots will be able to distinguish when someone is happy or sad. This allows them to respond more appropriately to the user.

The Jibo robot, arranged to ship later this year, is designed to be a personalized assistant. You can talk to the robot, ask it questions, and make requests for it to perform different tasks. The robot doesn’t just deliver general answers to questions; it responds bawd on what it learns about each individual in the household. It can do things such as reminding an elderly family member to take medicine or taking family photos.

Social robots are not just finding their way into the home. They have potential applications in everything from education to health care and are already finding their way into some of these spaces.

Fellow Robots is one company bringing social robots to the market. The company’s “Oshbot” robot is built to assist customers in a store, which can help the customers find items and help guide them to the product’s location in the store. It can also speak different languages and make recommendations for different items based on what the customer is shopping for.

The more interaction the robot has with humans, the more it learns. But Oshbot, like other social robots, is not intended to replace workers, but to work alongside other employees. “We have technologies to train social robots to do things not for us, but with us,” said Breazeal.