One of the most tedious, daunting tasks for undergraduate assistants in university research labs involves looking hours on end through a microscope at samples of material, trying to find monolayers.

These two-dimensional materials —less than 1/100,000th the width of a human hair—are highly sought for use in electronics, photonics, and optoelectronic devices because of their unique properties.

“Research labs hire armies of undergraduates to do nothing but look for monolayers,” says Jaime Cardenas, an assistant professor of optics at the University of Rochester. “It’s very tedious, and if you get tired, you might miss some of the monolayers or you might start making misidentifications.”

From action heroes to villainous assassins, biohybrid robots made of both living and artificial materials have been at the center of many sci-fi fantasies, inspiring today’s robotic innovations. It’s still a long way until human-like robots walk among us in our daily lives, but scientists from Japan are bringing us one step closer by crafting living human skin on robots. The method developed, presented June 9 in the journal Matter, not only gave a robotic finger skin-like texture, but also water-repellent and self-healing functions.

“The finger looks slightly ‘sweaty’ straight out of the culture medium,” says first author Shoji Takeuchi, a professor at the University of Tokyo, Japan. “Since the finger is driven by an electric motor, it is also interesting to hear the clicking sounds of the motor in harmony with a finger that looks just like a real one.”

Looking “real” like a human is one of the top priorities for humanoid robots that are often tasked to interact with humans in healthcare and service industries. A human-like appearance can improve communication efficiency and evoke likability. While current silicone skin made for robots can mimic human appearance, it falls short when it comes to delicate textures like wrinkles and lacks skin-specific functions. Attempts at fabricating living skin sheets to cover robots have also had limited success, since it’s challenging to conform them to dynamic objects with uneven surfaces.

A team of researchers at Korea Advanced Institute of Science and Technology, working with one colleague from MIT and another from the University of Stuttgart, has developed a biomimetic elastomeric robot skin that has tactile sensing abilities. Their work has been published in the journal Science Robotics.

Roboticists continue to work on improving robot abilities and to make them more human-like. In this new effort, the researchers gave a robot arm the ability to detect such sensations as a pat, tickling, wind, or something stroking its surface. They accomplished this by partially imitating human skin.

The new robot skin is multi-layered, like human skin, to allow for different functions. The top layer is made of a rubber-like polymer resembling human skin. Beneath that, the researchers added a hydrogel to imitate the human epidermis. They chose a hydrogel because it not only deforms when pressed, but jiggles when bumped. By embedding sensors to detect these reactions, the skin is able to sense things like a finger press by monitoring the pressure of the hydrogel and the direction of its movement. If something taps against it, the system senses and measures ripples in the hydrogel to gauge what the tap felt like.