Tactile, elastic, ultra-thin: New electronic skin improves robot control

The skin is full of sensors that absorb information from the environment. Researchers have used simple means to create an electronic skin that transfers this information to prostheses or robots for better control.

You can see a computer hand and a human hand touching each other.

Portuguese and US scientists have found a simple way to make electronic skin, including integrated microelectronics.

Photo: Panthermedia.net/AndreyPopov

The human skin surface contains a wealth of pressure and temperature and push buttons. They take information from the environment and process it. Specially designed electronic sensors are used by scientists to provide robots and prostheses with these capabilities, transmit information or control them. Portuguese and US scientists have now developed a simple method that allows them to inexpensively produce ultra-thin, elastic electronic skin. Their results have been published in the journal Applied Materials & Interfaces. The electronic skin can be used as an interface for a wide variety of human-machine interactions. Examples are prostheses, robots and virtual reality (VR).

Human-machine interaction: The interface is the problem

In human-machine interaction (or human-machine communication Researchers are seeking and developing possibilities of direct or indirect interaction between humans and machines. The human being, the interface and the technical system ideally merge into a uniformly functioning man-machine system. Human-computer interaction (HCI) is a subset of it. She researches and develops technologies for the interface between humans and computers. One of the big challenges is the technical interface. Above all, it is difficult to transfer extremely fine circuits and tiny sensors to complex three-dimensional surfaces. The electronics must remain bendable and stretchable and at the same time function stably. Finally, it is constantly being moved, stretched, bent, bent, or pulled.

Conventional electronic tattoos are expensive.

Some scientists have already created various forms of electronic skin, also known as electronic tattoos or e-tattoos. Similar to tattoos from chewing gum packages, they are applied to the skin, for example on the index finger. They pass touches over short distances as commands to the respective terminal. Essentially, they are intended for simple, but also for complex control commands.

The advantage: The control of the e-tattoos works intuitively and without eye contact, because people are always aware of the position of the e-tattoo on the body , However, the widespread production is complicated, expensive and requires clean room conditions. A team of scientists led by Mahmoud Tavakoli from the Institute of Robotics at the University of Coimbra (Portugal) has now developed a fast and cost effective alternative.

Circuit template from the laser printer

For this purpose, the scientists used a desktop laser printer to copy a circuit template onto a special paper, which they then use with a digital printer thin silver ink coated. This is only liable to the printed toner ink. An additional gallium indium metal alloy of the silver coating increased the electrical conductivity and made the circuit more flexible. Finally, they attached electronics, such as microchips, to a conductive “glue” of vertically oriented magnetic particles. This was embedded in polyvinyl alcohol gel. The adhesive provides stable electrical contacts to microchips that are just 300 microns in edge length. The circuit itself is about 5 microns thick. All pressure and interface processes were performed at room temperature.

The produced electronic skin is soft, ultrathin and ductile. It can be wrapped around any three-dimensional surface and adheres to the human skin. The researchers now transferred the electronic tattoo to various objects and demonstrated various applications: they were able to control a robotic arm prosthesis, monitor the activity of human skeletal muscles and integrate the information from distance sensors into the 3D model of a hand.

More at:

  • VR-glove DextrES: Realistic touch easy made
  • VR glasses: why they cause sea sickness in many people
  • Quiz: Virtual Reality