The term ‘bionics’ is relatively new combining the prefix ‘bio’ – meaning life – with electronics. Bionic technologies create mechanical or electronic versions of living things or body parts. Bionics is a science of constructing artificial systems that have some of the characteristics of living systems.
Bionics is not a specialized science but an interscience discipline; it may be compared with cybernetics. Bionics and cybernetics have been called the two sides of the same coin. Both use models of living systems, bionics in order to find new ideas for useful artificial machines and systems, cybernetics to seek the explanation of living beings’ behavior.
Bionics is the application of biological principles to the study and design of engineering systems, especially electronic systems. More simply put, it is man’s way to control his own adaptations with the use of technology. Examples of common bionic devices are pace makers, cochlear implants, artificial joints, etc. Cybernetics deals most with the examples given. It is that part of bionics that will show most development in the future.
Application of Bionics Bionic limbs
Artificial limbs have been around for hundreds of years. For instance, the Anglesey wooden leg was designed for the Marquis of Anglesey after he lost a leg in the Battle of Waterloo in 1815. Such a replacement body part is known as prosthesis.
Prostheses can also be internal parts, such as artificial knees, hips or even false teeth. But what’s different about the new generation of body parts is the way they combine several areas of technology and science such as electronics, biotechnology, hydraulics, computerization, medicine and nanotechnology.
The i-LIMB for instance, is an artificial hand with four independently powered fingers and a thumb. Each digit has a small motor and people using the artificial hand can grasp and pick things up, use scissors and even play cards. The i-LIMB attaches to the person’s arm stump and picks up small, electrical signals from muscles in the arm to control movement of the digits.
A different type of bionic hand is the award- winning rehab glove designed in Sydney. Using a computer and artificial muscles, the glove allows people with paralysed or injured hands to move their hand or grasp objects.
Although artificial legs and knees have been around for some time, now they are incorporating hydraulics, electronics and computer programming. These bionic legs enable better movement control by responding to the body and walking conditions. Other technology that uses electrical stimulation of the body’s existing muscles enables paraplegics to walk again.
Artificial cardiac pacemakers that use electrical impulses to regulate a person’s heartbeat have been used for around 50 years. More recent is the development of artificial hearts; for not these remain short-term treatments often used to buy time until a heart transplant becomes available.
The Abercorn artificial heart consists of a hydraulic pumping system which is totally implanted in the patient’s chest. An internal battery and electronics package are implanted in the patient’s abdomen to monitor and control the pumping of the heart. It is used for patients who have a life Expectancy of less than 30 days and no other viable treatment options such as a heart transplant. The first recipient, Robert Tools, lived for 150 days with the artificial heart before dying in 2001. Another patient lived for more than 500 days with his artificial heart.
The cochlear implant, or bionic ear as it’s often called, is one of the big success stories of medical bionics. The technology was developed by Professor Graeme Clark and his team at the University of Melbourne in the 1960s. Deafness is often caused by damage to the minute hairs in the ear; these normally turn sound into tiny electrical signals that the cochlear nerve then sends to the brain.
The bionic ear uses an external microphone that picks up sounds which are then sent via a processor to the implant. There, a receiver turns the sound signals into electrical impulses, which are sent via an electrode array to the brain.
Cochlear implants were under development about a quarter of a century ago and since its approval in 1984 has been widely used. Scientists are constantly improving the cochlear implant technology. The challenge now is to improve the clarity of hearing for recipients of the implant, particularly in places like crowded rooms or when listening to music.
The Australian government has allocated $50 million to fast track research into the bionic eye. Developing a bionic eye is a challenging task; scientists are meeting the challenge from a couple of different angles. There are three main types of bionic eye being developed around the world. These usually involve one of the following approaches:
i. Electrical stimulation of the retina, where images from an external camera are transmitted to a microchip on the retina wall or the eyeball, with electrodes stimulating the optic nerve to send signals to the brain.
ii. ‘Mini telescopes’ implanted into the eye that magnify images onto the retina. Such implants are being developed for people suffering from macular degeneration; and bypassing the eye, where the image information collected by a tiny external camera is sent to a processor then to electrodes implanted in the brain.
Although early trials have proved promising, so far there is very limited resolution or detail in what a person can see using such devices. But it is still early days and the technology is developing rapidly.
One of the most challenging areas of bionics is to allow a person to control a bionic device by using their brain – in effect, turning their thoughts into actions. Already scientists are developing implanted neural interfaces – nerve interfaces or brain implants – to help achieve this.
One team has reported being able to assist a quadriplegic check emails and plays video games using a computer chip implanted on the surface of his brain. Elsewhere brain-computer interfaces are being developed that let people move their wheelchairs around objects using electrical signals from their brain.
In other developments, researchers are looking at implanting electrodes in a person’s brain – known as deep brain stimulation or a ‘brain pacemaker’ – to treat Alzheimer’s disease, depression, epilepsy or Parkinson’s disease.
Incredible as it might seem, a new area of bionics is also being developed using nanotechnology. Known as nanobionics, it involves the use of tiny electrical circuits and materials made at the atomic or molecular level.
At such a scale, tissues of the body can be targeted more effectively and bionic technologies can be miniaturized. For instance, Australian researchers are looking at using minute carbon annotates to help implants connect better with living tissues and nerves.
The technology may contribute to the next generation of bionic ears: naruoelectrodes could improve the implant’s connection with nerves compared to the current platinum electrodes.
Similarly, nanobionics is being embraced to help repair spinal cord injuries – or other damaged nerves. Implanted nanoscale materials like carbon annotates can be used to encourage growth of damaged nerves and at the same time guide the direction of their growth.
While the safety of carbon annotates is yet to be confirmed, Australian scientists are trialing implants using intelligent plastics which – with electric stimulation – can deliver molecules that encourage nerve growth.