Source: EPFLScientists from the École polytechnique fédérale de Lausanne (EPFL) in Switzerland have created a soft artificial skin that offers haptic feedback and that is also capable of immediately adapting to the wearer’s movements.

Teams from EPFL’s Reconfigurable Robotics Lab (RRL) and the Laboratory for Soft Bioelectronic Interfaces (LSBI) developed the artificial skin, which is composed of silicone, electrodes and a network of soft sensors and actuators that enable haptic feedback — which is technology that replicates human sense of touch — producing a realistic sense of touch.

The soft pneumatic actuators create a membrane layer that inflates when air is pumped into it. According to the team, the actuators can be adjusted to a range of different pressures and frequencies — up to 100 Hz or 100 impulses per second. Once it is either rapidly inflated or deflated, the artificial skin membrane will vibrate.

On top of the artificial skin's membrane layer is a sensor layer that houses soft electrodes composed of a liquid-solid gallium mix. The electrodes continuously measure the skin’s deformation, sending data to a microcontroller that uses the feedback to adjust the sensation communicated to the wearer in response to their movements and changes in external factors.

“This is the first time we have developed an entirely soft artificial skin where both sensors and actuators are integrated,” said Harshal Sonar, the study’s lead author. “This gives us closed-loop control, which means we can accurately and reliably modulate the vibratory stimulation felt by the user. This is ideal for wearable applications, such as for testing a patient’s proprioception in medical applications.”

In addition to medical applications, the team also envisions that the artificial skin will have applications for virtual reality.

“The next step will be to develop a fully wearable prototype for applications in rehabilitation and virtual and augmented reality,” explained Sonar. “The prototype will also be tested in neuroscientific studies, where it can be used to stimulate the human body while researchers study dynamic brain activity in magnetic resonance experiments.”

The research appears in the journal Soft Robotics.