Robots With The Sense Of Touch

A team of researchers from the University of Houston (UH) has reported a breakthrough in stretchable electronics that can serve as an artificial skin, allowing a robotic hand to sense the difference between hot and cold, while also offering advantages for a wide range of biomedical devices.

Cunjiang Yu, Bill D. Cook Assistant Professor of mechanical engineering and lead author for the paper, said the work is the first to create a semiconductor in a rubber composite format, designed to allow the electronic components to retain functionality even after the material is stretched by 50 percent. The semiconductor in rubber composite format enables stretchability without any special mechanical structure. Yu noted that traditional semiconductors are brittle and using them in otherwise stretchable materials has required a complicated system of mechanical accommodations. “That’s both more complex and less stable than the new discovery, as well as more expensive.”

Our strategy has advantages for simple fabrication, scalable manufacturing, high-density integration, large strain tolerance and low cost,” he said.

Yu and the rest of the team – co-authors include first author Hae-Jin Kim, Kyoseung Sim and Anish Thukral, all with the UH Cullen College of Engineering – created the electronic skin and used it to demonstrate that a robotic hand could sense the temperature of hot and iced water in a cup. The skin also was able to interpret computer signals sent to the hand and reproduce the signals as .

The robotic skin can translate the gesture to readable letters that a person like me can understand and read,” Yu said.

The work is reported in the journal Science Advances.


Perfect Artificial Skin For Robots

A pioneering new technique to produce high-quality, low cost graphene could pave the way for the development of the first truly flexibleelectronic skin’, that could be used in robots.

Researchers from the University of Exeter (UK) have discovered an innovative new method to produce the wonder material Graphene significantly cheaper, and easier, than previously possible.

The research team, led by Professor Monica Craciun, have used this new technique to create the first transparent and flexible touch-sensor that could enable the development of artificial skin for use in robot manufacturing. Professor Craciun, from Exeter’s Engineering department, believes the new discovery could pave the way for “a graphene-driven industrial revolution” to take place.

robot female

The vision for a ‘graphene-driven industrial revolution’ is motivating intensive research on the synthesis of high quality and low cost graphene. Currently, industrial graphene is produced using a technique called Chemical Vapour Deposition (CVD). Although there have been significant advances in recent years in this technique, it is still an expensive and time consuming process, ”she said.

The Exeter researchers have now discovered a new technique, which grows graphene in an industrial cold wall CVD system, a state-of-the-art piece of equipment recently developed by UK graphene company Moorfield.

This so-called nanoCVD system is based on a concept already used for other manufacturing purposes in the semiconductor industry. This shows to the semiconductor industry for the very first time a way to potentially mass produce graphene with present facilities rather than requiring them to build new manufacturing plants. This new technique grows graphene 100 times faster than conventional methods, reduces costs by 99 % and has enhanced electronic quality.

These research findings are published in the journal Advanced Materials.


Smart Skin For Robots Simulating Sense Of Touch

It’s soft, warm, and can sense pressure, heat and humidity – just like human skin. This is ‘smartartificial skin and it’s the first to simulate the sense of touch. Its developers at South Korea’s Seoul National University say they aimed to create a material as close to human skin as possible.
prosthetic smart skin
We developed the synthetic skin which has the sense of feeling that exactly copies human skin. The skin can feel pressure, temperature, strain, humidity. Also it is soft, just like human skin, and embedded with heating elements that can make itself warm,” says Professor Kim Dae-Hong from the School of Chemical and Biological Engineering at Seoul National University. The warm prosthetic skin matches the temperature of the human body. And its layers give it its sense of touch.
The bottom layer of skin is rubbery material that can express the softness of human skin. Above the rubber layer, there is ultra thin polyimide and then silicon, which acts as sensors“, he adds. Researchers have combined their stretchy skin with a prosthetic hand and found it can be used for complex operations. Hand-shaking, keyboard-tapping and ball-grasping are all possible. And its humidity sensors mean it can even tell the difference between a dry diaper and a wet one. The researchers hope the ultra-thin skin will be able to send sensory signals to the brain. At the moment, this has only been demonstrated in small animals. But Professor Kim has high hopes for the future of his team’s prosthetic skin: “I hope a robotic limb with this synthetic skin can be used by disabled people. For industrial uses, it can be applied to various types of robots, like a humanoid robot“, he says. The developers envisage the synthetic skin being used by amputees. But a diaper-changing robot could also come in handy.

Electronics You Can Bend And Stretch

Stretchable material technologies have enabled an emerging range of applications that are impossible to achieve using conventional rigid or flexible technologies. Examples can be found in diverse application domains such as roboticS and automation, health care and biomedical technologies, and consumer electronics. The ability to deform a functional substrate so that it can be wrapped around a curved or moving surface, allows for example creating an artificial (robot) skin, wearable on-body sensing systems, or even monitoring moving machine parts or electronic systems that conform to their environment.
Now a team from Gent University in Belgium has developed the first optical circuit that uses interconnections that are not only bendable, but also stretchable using a stretchable material, polydimethylsiloxane (PDMS). Nowadays, more and more (sensing) systems are implemented using optical instead of electrical technologies and it can therefore be expected that in addition to stretchable electrical interconnections, there will also be a need for stretchable optical interconnections.

electronics to bend and stretch
The researchers introduce the concept of stretchable optical interconnections based on multimode PDMS waveguides. To adopt a widely applicable and cost-efficient technology, only commercially available materials are used and the waveguides are patterned using a replication technology based on the capillary filling of PDMS microchannels.


Artificial Skin For Robots Like Human Skin

Researchers from the Georgia Institute of Technology have fabricated arrays of piezotronic transistors capable of converting mechanical motion directly into electronic controlling signals. The arrays could help give robots a more adaptive sense of touch. Mimicking the sense of touch electronically has been challenging, and is now done by measuring changes in resistance prompted by mechanical touch. The devices developed By Georgia Tech scientists rely on a different physical phenomenon – tiny polarization charges formed when piezoelectric materials such as zinc oxide are moved or placed under strain. In the piezotronic transistors, the piezoelectric charges control the flow of current through the wires just as gate voltages do in conventional three-terminal transistors.


Any mechanical motion, such as the movement of arms or the fingers of a robot, could be translated to control signals,” explained Zhong Lin Wang, a Regents’ professor and Hightower Chair in the School of Materials Science and Engineering at the Georgia Institute of Technology. “This could make artificial skin smarter and more like the human skin. It would allow the skin to feel activity on the surface.