Bionics is a scientific and technical discipline that takes ideas from biological systems to design engineering systems. It is sometimes called as Biomimetics or Biomimicry. Bionics involves multidisciplinary approach finding inspiration from biological systems to define new engineering problems. It is a newly emerged branch of science that uses the knowledge from electronics, informatics, medicine, biology etc.
The word ‘Bionics’ is derived from a Greek word’ Bion’ which means ‘unit of life’ with a suffix ‘ic’ meaning ‘similar’. But it is also believed that the word bionics is formed of biology and electronics.
The idea of bionics came from the success of living organisms in solving problems in their environment. Natural selection will operate in nature to make the organisms well adapted to their environment. Such biological methods and solutions provided an insight to develop engineering systems in an alternate way.
Bionics involves ‘ReverseEngineering’ methods and principles of design found in living organisms. The problems encountered by living organisms are identical in many respects to the problems in engineering systems. Therefore it is logical to analyze the problems in engineering by examining the biological solutions of living organisms. But implementation of biological solutions to an engineering system is not straightforward because both systems vary in many aspects. For example, engineered structures are homogenous with straight structures while living organisms are composed of heterogeneous substances and their body plan is cylindrical in most cases.
But a bionic approach may be a good starting point to solve the problems in engineering systems. For example, flapping movement of bird wing can be utilized to design aircraft systems. Some of the engineering systems imitating the biological systems are Radar system (echolocation of bats), Smart cloths (opening of scales in pine cone), implantable artificial heart AbioCor etc.
Many researches are going on in biologically inspired projects like generation of bio-electricity, development of artificial limbs, ear, eye etc. The development of DNA chips and other bionics products will improve the quality of human life through the use of bionics products in medical and health services. Research is also going on to design bionics systems for the use in space vehicles. Another potential application is the use of bio-sensors, Biomimetics receptors etc. in aeronautics and autonomous orbital systems. Bio inspired artificial intelligence for data management system also has potential application in aeronautics and space navigation.
Till now there is no general methodology to give a systematic approach to bionics. The first step in engineering design is identification of the system to be developed and its important parameters. But in bionics, to develop a system, one has to identify a possible system from all the biological systems available in nature and then comparing with the engineering that is to be developed. This type of methodology is known as ‘Concept development”. It forms the critical phase in bionics. It applies all the possible aspects of living system to achieve functions in the engineering system that is to be developed.
DNA is the molecular electronic unit made by the nature. It stores, processes and provides informations for growth and maintenance of living organisms. The key component of DNA for molecular electronics is its ‘nucleotides’ composing of nitrogen bases, phosphate and sugar. The joining of two DNA strands to form a DNA double helix is similar to two bases of conventional electronics,”0” and”1”.DNA self assemble components 1000 times as dense as the best processor circuit and 100 times better than any data storage circuit. Molecular electronics uses mainly DNA as active components. A DNA strand joining two metal atoms contact can function as a molecular electronic device.
The DNA chips opened a new era in medical research and medical diagnostics. The DNA chip can provide large quantity of genomic data of microorganisms in a few hours, so that identification of the microbe is very easy. A DNA chip is a ” Micro array” of genes attached at fixed locations on a solid support like glass slide or silicon membrane. The chip has microscopic DNA spots that allow massive genetic analysis.
The DNA chip works on the principle that the complementary nitrogen bases of DNA join together. A hypothetical DNA chip with 8×8 squares containing a total of 64 squares. If 3 nucleotides are put in each square, then there will be a total of 64 sequences each having 3 nucleotides. If a DNA segment of unknown sequence with 3 nucleotide is rolled over the DNA chip, it will’ stick’ to the sequence in the chip complementary to it. So it is easy to identify the unknown base sequence.
DNA Chips have many applications such as Gene profiling, Comparative gene hybridization, Single-nucleotide polymorphism and Genome sequence analysis. Silicon based DNA Chips are now used in DNA Micro array hybridization. DNA Chips have emerged as a tool for detecting human genetic diseases and disease causing pathogens. There are more than 125 companies engaging in DNA Chip design and development. The manufacturing process involves many electrochemical, chemical and photolithic processes. This makes the DNA Chip development costly.
Bionics is exploring the development of disposable biochips to test various diseases to get instant results. It is very interesting that many of our body fluids such as saliva, tear, urine, blood can be utilized to generate bioelectricity. These fluids are rich in electrically charged ions. Development of Micro-Electro Mechanical Systems (MEMS) and Nano Devices are expanding for human applications. One such bioelectricity generator called “Paper Battery” has been developed by Prof. K.B.Lee in Singapore to generate bioelectricity from urine. This paper battery can be integrated with electronic devices to supply current upon contact with urine.
The Paper Battery consists of a paper socked in Copper chloride solution and sandwiched between two strips of Magnesium and Copper. The laminated form of this paper battery generates 1.5 volts with a power of 1.5 mW when 0.2 ml urine is added through a slit provided in the laminated surface. The current and voltage of this ‘Credit Card’ size battery is sufficient to run a low power electronic device for around one hour. The paper battery is ‘biodegradable’ and can also be activated by saliva.
Human body generates heat through metabolism and this heat is emitted in the form of Passive Infrared Rays (PIR). By utilizing the energy from the body heat, Seiko developed a biowatch which totally depends on the body heat for the energy required for its functioning. This “Thermionic Watch” absorbs heat from the wrist and dissipates it through the front side of the watch. The internal thermoelectric generator converts the temperature into electricity and drives the watch. The heat powered Thermic watches utilizes heat energy continuously while wearing on the wrist. The memory chip inside the watch will keeps tracks of time even when not in contact with the body.
Research is going on the Brain-Machine interface (BMI) that allows human brain to accept and control a mechanical device as a part of the body. Data can flow from the brain to the outside machinery or to brain from the machinery. Researchers at Infineon have developed a “Neurochip” to record and process electrical signals from nerve cells. The Neurochip can be implanted inside the brain. It is a tiny chip (4mm2) called ”Brain Gate” that will amplify the brain signals generated by a thought and transfer them to a computer system for processing.
One major goal of such research is to create a system that allows patients who have damaged nerves to activate outside mechanism. Paralysed person will be able to operate computers, instruments etc by thought alone. Cyber kinetics Inc, a pioneer in nanotechnology has developed the first implantable “Brain Computer Interface” that can interpret brain signals and read decisions of brain to develop a fast connection between the brain of a severely disabled person and a personal computer.
Research is going on in ‘integration’ and ‘on-board’ data processing. This has led to the development of a novel ‘Microelectronic Pill’ of 10 mm diameter and 30 mm long weighing 5gm. When it is swallowed, it will pass through the alimentary canal and make physiological analysis in the body such as temperature, pH, conductivity, dissolved oxygen amount etc. The ‘pill’ will come out of the body by normal bowel movements. The electronic pill has an outer ‘biocompatible’ cover enclosing ‘Microsensors’, ‘Controlchips’,’Radio transmitter’ and two ‘Silver oxide batteries’. This Magic pill can detect the abnormalities in the gastrointestinal tract and transmit the ‘data’ to doctors.
UV University Medical Centre, Amsterdam developed an implantable Pacemaker to keep heart beat rhythm normal. The pace maker has an advanced ‘transmitter’ that intimate the cardiologist by SMS about the cardiac rhythm failure. The SMS automatically alarms the mobile phone of the treating physician so that he can immediately respond.
Biosentinent, Houston, USA is developing an electronic device to monitor the autonomous nervous system of the body. It can pickup changes in the rate of heart beat, breathing rate etc and helps to monitor anxiety, neurological complications etc. The device has sensors which are incorporated in the wearing cloth and the recorded data will be displayed on a wrist meter or transmitted to the doctor.
GeoView and German clothing company FalKe KG have developed an ECG shirt to monitor heart rate. The shirt has two sensors that constantly check the heart rate and the ‘recorded ECG’ will be transmitted to the mobile phone through ‘bluetooth’ connection.
Researchers at the University of Nebraska, USA have shown that bacteria coated with ‘gold nano particles’ can act as ‘humidity sensors’. They produced a chip covered with fine ‘gold electrodes’ and applied it to the bacterial surface. The bacteria Bacillus cereus thus became a ‘biosensor’ to measure humidity changes in the atmosphere.
With the use of modern information technology, reserchers have developed an Artificial Silicon Retina (ASR) for the people who have lost some retinal cells due to aging or disease. It is a silicon chip 2mm diameter and 25 microns thick less than the thickness of a hair. It contains around 5000 microscopic solar cells called ‘micro photodiodes’ each will have its own stimulatory electrodes. These micro photodiodes converts light energy from the images into electro-chemical impulses that stimulate the remaining functional retinal cells of the eye. The chip is powered solely by the incident light and does not require batteries or connecting wires. The chip can be implanted under the retina of the eye.
Biomechatronics combines biology, mechanics and electronics and focus on the interactivity of human organs including brain with electromechanical devices. Application of mechatronics includes pace makers, brain controlled electronic muscle stimulators, artificial limbs etc. The European Union project lab is developing a ‘Prosthetic hand’ capable of eliciting natural sensory signals.
The ‘Bionic Hand’ can be implanted in the human arm. Linked to nerves by tiny electrodes and biometric sensors, it would help the patients to sense position and movement of hand as well as to receive stimuli from outside environment. A ‘bone conducting transducer’ has also been developed for the people who have hearing impairment. It is an electromechanical transmitter that allows hearing of sound through the vibration of skull bones. The bone conduction process directs the audio signals to the inner ear through the cranial bones.
Bionics research is likely to remain an expert driver pursuit for sometime to come in the near future considering the difficulties in implementing guidelines across a wide field which involves many disciplines. Currently bionics is focusing on ‘mechanical joints’ inspired by nature but with the increasing use of systemic design practices in bionics design tools, bionics would continue to be an important issue for consideration of engineers to be recognized as a distinct discipline.
Improved performance is expected as new bionics design promise space and mass savings compared to conventional systems.