Researchers at Stanford University have successfully used light signals to stimulate muscle activity in mice. The concepts used in the experiment could one day form the basis of medical treatment for humans with a range of muscle-related conditions, including reversing the process to reduce involuntary muscle spasms.

The experiment began with using an algae-derived gene that was known to be responsive to light. This gene was inserted into the mice, leading to a light-sensitive protein forming on the surface of their nerve cells.

The researchers then placed a ring around each mouse, concentrating on the sciatic nerve. Each ring had a series of LEDs facing towards the mouse. They found that short bursts of blue light caused the nerve to induce muscle contractions.

Gizmag reports that the breakthrough is in the details of how this work. Previous tests using electrical impulses have worked to a limited extent on humans and animals, but only for a short time. That’s because the electricity was stimulating a particular type of nerve that is used for brief and intensive activity such as running. This meant the muscles those nerves stimulated were quickly exhausted. The light technique instead stimulates nerves associated with slower muscle activity.

To find the effects of this difference, the researchers also tested the electrical technique on the same mice. They found this lead to the muscles becoming exhausted after around four minutes, whereas with the light technique, the muscles still worked (albeit at around a third the peak force) after at least 20 minutes.

(Image for illustration only. Credit: Kappa Windscreens)

IBM has been looking into the concept of what would be the ultimate in tiny memory chips. And like any good scientific research, it’s all down to a super-powerful microscope.

The study is based on a remarkably simple premise. The best way to produce a smaller memory chip (or in turn, to get more capacity on the same size) is to find the smallest possible thing that can exist in two different states and thus represent one bit of digital information. And if you’re looking for something small, why not use an atom?

The first fundamental problem with making that a reality is that the way to put an atom into one of two states is to control its electron spin. That lasts for a much shorter period than the electrical charge used in tradition DRAM or Flash memory.

That in turn causes a problem when using the microscopic power needed to measure the electron spin (and thus retrieve data). A standard scanning tunneling microscope (a microscope capable of distinguishing individual atoms) is too slow to measure such detail and keep track of the spin.

IBM has now used a pulsed-STM microscope to tackle the problem. This involved sending out a pulse to put the spin into a known state, then measuring the state shortly after. The researchers then repeated this process with increasingly longer gaps between the pulse and the measurement, until the point at which the effects of the pulse were no longer measurable.

As a result it’s now known that a single iron atom can be forced into a state and held there for around 250 nanoseconds (250 billionths of a second) before being refreshed. To put that into context a standard DRAM cell needs refreshing every 50 milliseconds (50 thousandths of a seconds).

This isn’t a solution, but rather a case of at least understanding the precise question and the scale of the task. There’s already been some progress made: the 250 nanoseconds retention was achieved by placing the iron atom near a copper atom (without this, the iron atom only held the information for around one nanosecond).

But I wouldn’t throw that “bulky” memory card away quite yet.