Tag Archives: Innovation

Prosthetic Limbs approach the Natural kind

Advancements in the function of powered prosthetic limbs have been few and far between in the last 50 years. That is not to say that their structure and mechanical design have not improved, but current prostheses still limit the wearer’s motion control and sense of touch. Researchers at the Case Western Reserve University of Ohio recently performed a study in which they implemented pressure sensors to more closely mimic what a person with a normal arm would feel.

Prosthetic limbs aim to mimic real limbs by communicating directly with the brain. Image source: Gizmag

Touch perception, one of our five senses, is a critical part of the human experience and helps build our basic perception of the world around us. In humans, the somatosensory system (touch, or tactile perception) critically depends on the nervous system. When you touch a surface, for example placing your hand on a table, sensors on the skin’s surface initiate an electrical signal that is conducted to the brain via the spinal cord, and allows the impact to be felt by the hand. The term ‘stimulus’ simply refers to an electrical signal coursing through our body that is processed by our brain, and interpreted as an instruction for reaction. However, in individuals lacking normal limbs, this pathway cannot occur because the skin sensors are not present. In general, modern research in the field aims to improve two-way communication between the wearer and their prosthetic limb.


New technologies in prostheses aim to improve the communication between brain and limb. Image Source: Flickr commons; Uploader: U.S. FDA

Many people who currently wear prosthetic limbs complain that the appliances create unnatural sensations that are distracting and unpleasant. Moreover, current prosthetic limbs cannot directly convey stimulation to the wearers. Dr. Dustin Tyler and his colleagues at Case Western Reserve University proposed a solution for this problem. They hypothesized that if they could generate electrical signals in varying intensity to nerves (lying outside of the brain and spinal cord), this would produce sensory restoration. The team’s main improvements to the existing prostheses were as follows. Firstly, they created an ability for wearers to vary their grip strength, and secondly, they decreased the level of discomfort endured by the wearer.

In order to create a stimulation, the team connected electrodes that could create electrical impulses into the subjects’ upper limbs. Researchers also added pressure sensors to subjects’ artificial fingerprints that had the capacity to respond to varying stimulation patterns. Two parameters were tested. Firstly, by altering average signal intensity, researchers found that the wearer could precisely control the size of the area their hands were in contact with. Secondly, by changing signal frequency, researchers found that the wearer could control their finger strength. The combination of these two features gave wearers an enhanced ability to manipulate delicate objects. Also, users of the research team’s prosthetic limbs described the sensations as natural and comfortable.

The video below shows a prosthetic limb user performing the delicate task of removing a stem from a cherry. Those who were using nerve stimulation technology perform significantly better than those without it.

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-Imran Mitha


“Turbocharged” Photosynthesis – Wait what?!

Plants convert the sun’s energy into food. Source: Wikipedia Commons

Photosynthesis is a process that plants and other living organisms use to convert carbon dioxide, water and light energy into food. Sounds pretty amazing, right? But that’s only the start.  Photosynthesis single-handedly supplies all the organic compounds and nearly all the energy that is needed for life on Earth. Simply put, without photosynthesis we would not be alive today. In recent years, a question that has often been asked is whether photosynthesis can be tweaked such that the process becomes faster and more efficient.

-Click here for all the intricate details of photosynthesis! Also, the process is illustrated nicely in this short animated film:

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Micrograph of a cyanobacterial species; Synechococcus elongatus. Source: L.A. Sherman and D.M. Sherman, Purdue University

Crucial to photosynthesis is an enzyme called Rubisco. This enzyme is required in the conversion of carbon dioxide to sugar. However, the Rubisco found in plants is inefficient. And so, a team of American and British biologists came up with the idea to “borrow” genes for Rubisco from a cyanobacterial species, called Synechococcus elongates, and genetically engineer them into plants. Formerly known as blue-green algae, cyanobacteria specialize in photosynthesis. Consequently, researchers claim that by meddling with Rubisco in crops, photosynthesis can increase in efficiency by up to 60%.


In the aforementioned experiment, published in Nature, the team of researchers transferred bacterial genes and proteins, including Rubisco, into the tobacco plant, Nicotiana tabacum. As a result, this new hybrid plant could convert carbon dioxide to sugar faster than normal strains of the tobacco plant. When asked how her team of scientists was able to accomplish this feat where other teams had failed before, biochemist Maureen Hanson at Cornell University pointed to the fact that her team also transferrd additional proteins to assist the foreign Rubisco.


A bacterial enzyme was delivered to a sample of Tobacco Plant; Nicotiana tabacum. Source: Rothamsted Research

With crop production technology being a hot field of research, the implications of this study are immensely important. While human population continues to increase at staggeringly fast rates, there are continuously more mouths to feed. “Hacked photosynthesis” may be one way to alleviate the looming problem.

You may be wondering… when will these super-efficient plants be in crop fields near you? Not as soon as you might think. While turbocharged photosynthesis works great in theory, in reality there are a few setbacks. One issue is that cyanobacterial Rubisco has a tendency to react with oxygen. Bacteria deal with this problem by incorporating a protective capsule, called a carboxysome, to ward off oxygen. However, plants lack this defensive shell and so the tobacco plant with bacterial Rubisco wastes significant amounts of energy. Naturally, scientists are currently working on ways for plants to create structures resembling bacterial carboxysomes.


‘Turbo’ photosynthesis could redefine the way we farm crops. Source: Flickr commons, Uploader: Appe Plan

All in all, while the process of turbocharged photosynthesis has yet to be perfected, this scientific finding is a great leap in the direction of higher-yielding and faster-growing crops.

-Imran Mitha


Broken leg? Go print a new one…

Well, not really. But it might not be such a strange idea in the near future, as research into 3D printing continues to reveal incredible new uses for the technology.

3D-printing, professionally known as ‘additive manufacturing’ has already been around for a few decades, used to manufacture prototypes, or create cute desk ornaments and toys. Digital files contain the design of a model, and include instructions for the printer. Hundreds of different materials can be used, such as liquid plastics, powdered metals, nylon and ceramics. These materials are systematically hardened into a solid shape, with each successive layer forming a small part of the larger design.

One of the 3D printers widely available today on the market. Source: Flickr Commons user Creative Tools

Maker-Bot Replicator 2, one of the 3D printers widely available today on the market. Source: Flickr Commons user Creative Tools

We live in a world, however, where this kind of technology can do so much more than build ‘mini-me’ action figures. Imagine a natural disaster has just occurred in a remote location in the world, and only small aircrafts can reach the site. While it is still necessary to bring in medical professionals, some immediate aid can be provided in the form of 3D-printed casts, splints, and other medical supplies such as bandages and dressings. Syringe Extrusion, one method of additive technology, can use almost any liquid or paste to create a final product, meaning that one day we might even be able to 3D-print food, which would be particularly useful in situations like this one.

Now imagine an impoverished agricultural community, without the means to effectively sustain themselves. What can additive technology do for them? Machinery such as farm tractorswater pumps and tools for sustainable energy use (solar panels, wind turbines) can easily be printed and installed. This technology has the potential to increase the quality of life for many such communities, and the equipment would be cheaper than their mass-produced factory equivalents, due to the fact that 3D-printing eliminates the ‘assembly line’, so to speak. The power to create an object from widely available design software means that you won’t have the added costs associated with product development. Nor will you have any transportation costs, and this will also benefit the environment due to reduced CO2 emissions.

Arguably the most exciting use, though, is in the health industry. Researchers such as Ali Khademhosseini have been using this technology to ‘print’ natural sugar-based templates, on which to grow biological cells. These cells can then differentiate to grow different types of bodily tissue, including cardiac tissue and skin, which can be used in disease studies and drug therapy. For example, cancerous tumours have already been printed and reveal more about the specific proteins and characteristics of cancer than previous methods. Using these cells and tissues to test the effects of new drugs may also eliminate the controversial use of lab animals.

3D-printed ear and nose templates can be used to grow biological tissue. Source: Flickr Commons user UMHealthSystem

3D-printed ear and nose templates can be used to grow biological tissue. Source: Flickr Commons user UMHealthSystem

Transplant patients also benefit from 3D-printing; patients’ own cells are used to develop the needed tissues, thereby eliminating the risk of rejection of foreign transplants. Bone tissue is also being printed which may aid in the advancement of prosthetics, so who knows, maybe the title wasn’t so far off after all.

By Mikaela Stewart