Scitech Bulletin 1.5 — Let’s take it light

For many centuries, several scientists across the globe have sat down and endeavored to harness the full potential of light energy. We are far off from the times when the thought of controlling light was just a mere fantasy. Light undoubtedly is one of those few elements that plays a phenomenal role in our day-to-day lives. 
Light has found its applications in every field that exists today. In this SciTech Bulletin version 1.5, we bring to you some novel innovations powered by light over the years.

Role of light in Medical Technology - Give ears to the Light!

Humans have been provided with five sense organs to perceive various sensations. The eye is the organ most commonly associated with recognizing and utilizing light. The recent discovery that light from a pulsed laser can trigger auditory activity in hair cells is of great significance in the field of hearing aids and cochlea implants.

A cochlea implant is an electronic device, surgically implanted in the cochlea, or the inner ear of a person whose hearing is severely impaired in both ears. This helps in restoring hearing in people with “nerve deafness”, a condition in which the cochlea of the ear is damaged. Cochlea implants bypass damaged structures in the inner ear and directly stimulate the auditory nerve. Incoming sounds are converted to electrical currents and directed to a number of contact points on the internal wire. This operation creates an electrical field which directly stimulates the auditory nerve, thus bypassing the defective inner ear.

A major drawback of electrical stimulation is the possible electrical interference from the environment or between nearby electrodes that reduces the extent to which the stimulation can be localized and focused spatially. This causes unwanted effects like facial nerve twitching.

Cochlear implant

Using pulsed laser light as simulant will help overcome interference and difficulties with spatial resolution. CSEM (Centre Suisse d’Electronique et de Microtechnique), Switzerland is currently involved in the project ACTION (Active Implant for Optoacoustic Natural Sound enhancement).

For more information regarding this, click here: http://www.cmmmagazine.com/micromanufacturing/the-tiny-active-implants-that-could-make-the-difference/

Role of Light in Infrastructure - Translucent Concrete

Translucent concrete or transparent concrete is essentially a light transmitting concrete. The idea of this concrete mix was conceived in 2001 by the Hungarian architect Aronlosonzi.

The materials that make translucent concrete capable of emitting light are the combination of water, concrete, fine aggregates, coarse aggregates like crushed granite and optical fibers. In earlier experiments, transparent resins were used but yielded poor results. The optical fibers are arranged in a particular pattern in a mould, and the concrete prepared as per the standard mix is poured onto the arrangement of the fibres in fine layers, without void formations.

Translucent Concrete

The use of translucent concrete renders an aesthetic appeal to buildings. However, the main advantage of transparent concrete is that it is a key player in green buildings. This light transmitting concrete allows light from natural( sunlight ) and artificial sources pass through it, thereby reducing the use of electric lights to meet the demands of lighting. Thus it provides for clean energy and saves energy cost as well as consumption. In colder places, it provides for insulation as it transmits heat with sunlight. Transparent concrete is also regarded to have a good strength and is frost and deicing resistant. The only drawback of this innovation is the high cost owing to the use of fiber optics.

For more information click here: 
http://illumin.usc.edu/245/translucent-concrete-an-emerging-material/

Role of light in X-Ray Astronomy

Pulsars are spinning and pulsating stars that emit radio and (or) gamma rays. Studies from research reveal that the nebulae of pulsars resembles the shape of a jellyfish.

However, with the data from the Chandra X-ray Observatory of two pulsars (Geminga and B0355+54) has some new discovery on the the geometry of pulsars has been made.
The two pulsars, Geminga and B0355+54 pulsars share many similar characteristics even though they’re 800 and 3400 light years away from earth. They’re about the same age and have same rotational periods. However, Geminga emits only gamma-ray pulses while B0355+54 emits no observable gamma rays and emits the brightest radio waves.

Double tailed Pulsar

Their different geometry has helped astronomers understand new properties of the pulsar and provide evidence to create models of pulsars. Also, it is believed that further studies in pulsars will help estimate the total number of exploded stars in our galaxy.

Finally, this use of X-Ray technology will lead to the discovery of celestial objects well hidden and out of reach in the farthest corners of the universe.

For more information on this development, click here: http://www.universetoday.com/133001/space-jellyfish-show-types-pulsar-wind-nebulas/

Role of Light In the Electronics world - Blue LEDs

Three scientists were awarded the prestigious Nobel Prize for Physics in the year 2014 for the invention of the blue LED — a development that came to fruition in the 1990s. However, the Nobel Prize is usually awarded to an invention or a discovery that has the potential to be of “the greatest benefit to mankind”. But, what could power a thing like blue LEDs to that position — one where it’s supposed to be of paramount importance to the world?
Without blue LEDs, it wouldn’t be possible to combine red, blue and green colors, to achieve White LEDs. White LEDs are touted to be the next best thing in powering up homes all around the world, with minimal energy and financial consumption. Blue LEDs also are now extensively a part of smartphone, computer and TV screens.

The white LED, which is achieved from the blue LED by the usage of excitation from a fluorescent chemical source in the bulb which hosts the LED. This white LED lasts 10 times longer than the widely in use, incandescent light bulb. It has a comparably higher rate of conversion of electricity to light. The white LED can convert more than a fifty percent of its electrical input into light, which is comparatively higher than the modern light bulb, which has a conversion rate of a meagre four percent. This technology is expected to power almost 1.5 billion people of the planet, who otherwise couldn’t afford proper electrical facilities.

In the future, the combining of three different kinds of LEDs mentioned above — red, blue and green — may be extensively used in producing a special kind of white LEDs, which may result in a spectrum of tunable colors. This means great growth in the technological aspects of many fields.

For more information on blue LEDS, click here: 
https://medium.com/starts-with-a-*bang/why-blue-leds-are-worth-a-nobel-prize-2b5ff8c22803#.78dym96cj

Role of light in communication - Li-Fi

One day, a professor named Haas Harald from the University of Edinburgh, introduced a new word to the world, “LiFi”.

Li-Fi also known as Light Fidelity, uses the VLC or Visible Light Communications technology for transmission of vast amount of data in a short span of time. Li-Fi pretty much like WiFi uses electromagnetic waves to transfer data, with the only difference being that WiFi uses radio waves whereas LiFi uses Light. LiFi uses a very simple system to achieve this process. It generally comprises of two main parts- a photodiode equipped device to detect the light signals and of course, a unit that plays a role in signal processing.

The process demands massive modulation and demodulation of signals. This fast paced amplification is achieved through the use of LEDs. The rapid flickering is generally invisible to the naked eye. Once the signal gets demodulated, it gets converted into binary data which we perceive as Web, audio and video.

For more details, visit: 
http://purelifi.com/what_is_li-fi/

To read the previous Scitech Bulletins, click here.