Digital Skin' Activates Brain Cells

Flexible Sensor to Identify Touch

Flexible sensor that can identify touch, just like skin, producing electrical pulses that can get faster when the pressure tends to increase, have been built by engineers. These pulses have also been utilised to drive neuronal activity in a slice of mouse brain.

 It is said that the system seems to be more a replica of touch sensation for many other designs of artificial skin, making it a hopeful choice for the progress of responsive prosthetics. This has appeared in Science magazine.

According to senior author Zhenan Bao, the foremost benefit is that the bendy plastic based sensor tends to directly create a pattern of pulses which produces sense to the nervous system. She informed BBC that earlier, with plastic material those in the field were able to make sensitive touch sensors but the electrical signal which comes from the sensor does not seem to be the right format for the brain to be capable of interpreting it.

This means that other designs though they have developed some notable results in test with the patients, needed a processor or a computer to translate the touch information. Prof Bao, chemical engineer at Stanford University informed that now the sensor is coupled with a printed simple electronic circuit which enables the sensor to generate electrical pulses which can communicate with the brain.

First Step towards Use of Plastic Material for Artificial Skin

She considers this as the first step towards the use of plastic materials for artificial skin on prosthetic limbs. She adds that the sensors could prove to be useful in wearable technology. They seem to be very thin and flexible as well as stretchy and one could mount a sensor on the skin and use it in identifying vital signs like heartbeat and blood pressure.

The nature of the design is a layer of rubbery, flexible polymer which is laced with carbon nanotubes, shaped into tiny pyramids. The semi conductive layer provides a reading of the pressure,when sensors tend to get squashed Prof Bao clarified that when pressure is applied, the pyramids tend to get deformed and the top becomes more flat. This tends to change the amount of current which can flow though these pyramids.

 Below the layer there is an inkjet printed circuit known as oscillator that turns the variable current into a train of pulses. With added pressure as well as current, the rate of the pulses seems to go up.

Light Based Technique – Optogenetics – Utilised By Neuroscientists

Prof Bao together with his colleagues, to demonstrate that this signal can relate reliablywith the nervous system, passed it to a blue LED and shone the light on a slice of brain of a mouse. The subset of brain cells there had been engineered to react to this stimulation by expressing a light sensitive channel which floods the cell with the charge when it was hit by blue photons.

When the scientists measured the impulses of individual cells in the slice, they envisaged correct details of the pulses that were produced by the touch sensor and flashed by the light, even when they were moving fast out at 200 pulses per second.

This light based technique considered as optogenetics is utilised by neuroscientist for all types of experiments inclusive of manipulating memories by driving activity in certain sets of neurons. This was chosen by Prof Bao’s team since delivering electricity directly to nerve cells often seems to be a problem.