Bio-inspired Technologies

Lead Research Organisation: Imperial College London
Department Name: Institute of Biomedical Engineering


The research activities of the Bionics group at the Institute of Biomedical Engineering, Imperial College London have concentrated on providing intelligent, physiological semiconductor chips based on models of the biological behaviour of the retina, cochlea, neurons, beta-cells, etc. The current research focus at IBE is in the area of bio-inspired technologies, which is a cross-disciplinary field at the interface between biology/biochemistry, physics/engineering and medicine. We design electronic systems that interact with human organs and systems, as well as: electronic circuits and devices designed following the basic principles of biological systems. Here we propose a set of feasibility studies which are based on applying state of the art engineering technologies to provide solutions for intricate physiological and medical problems, such as selective neural stimulators or implants. Equally, we are deriving new technologies based on complex biological systems and biochemical processes, such as cell signalling mechanisms. This investment will lead to research which will provide proof of principle for several exciting new ideas; and if successful will be developed commercially and have a significant impact on healthcare as well as certain widespread devices such as mobile phone cameras, or sensitive chemical detector arrays. The Feasibility Account will be used for a suite of five research themes. The first theme will explore the feasibility of converting the phototransduction process in an invertebrate's photoreceptor - a cascade of biological amplifiers - into electronic equivalents. The second theme ventures into a completely new research field of memristors - passive memory devices. The other three themes assess new strategic paths in neural stimulation and neural prosthesis design: combined optical and electrical stimulation for achieving selectivity, then use of a photosynthetic reaction centre for imparting light sensitivity of neurons and muscles, and eventually the use of noise to enhance sensory perception in human auditory pathways.

Planned Impact

The immediate impact of the feasibility studies research, which is relatively short and high risk, will be mainly scientific output. The results of the studies will be scrutinized (and possibly enhanced) through the peer review process and we should produce several high quality journal publications. At that stage the results will start to have an impact on academia, when other scientists will be able to use the results of the feasibility studies. There will also be a strong impact on the careers of the researchers involved as well as for the Institute and Imperial College in further developing, strengthening and consolidating the cross-disciplinary culture. This project has the potential to develop up to five long term research programmes at the IBE, all of strategic importance to us, with potential to commercialise. The long term impact is the potential to enhance quality of life and health. If proven possible, activity (1.1) could lead, after the development phase and technology transfer, to the creation of ultra-sensitive imaging chips and chemical detector arrays. These devices will be important for the mobile phone camera markets and for security applications. The memristor research (1.2) can have a long term academic impact, and because this is cutting edge science, any breakthrough in this area would result in becoming a leader in the field. Similarly, the Photosystem I research, where ISFET devices and circuits will be used to monitor the efficiency of PSI light absorption, will also have scientific impact. The research theme (2.1) Combined neural stimulation, pushes the boundaries of fusing engineering with biology, but the results will be groundbreaking, finally bringing implantable stimulation into mainstream medicine. This will offer a breakthrough in the treatment of serious medical conditions affecting a significant number of people globally, such as treatment-resistant epilepsy, Parkinson's disease, severe obesity and clinical depression, which are considered to be practically incurable today. Together with theme (2.3) Stochastic resonance in the central auditory system, it could have significant impact in the area of neural prostheses, so the targeted long term beneficiaries will be disabled people, in particular those who suffer from deafness, blindness, or balancing problems, as well as the people with severe types of depression or Parkinson's disease. To ensure that the potential beneficiaries have the opportunity to benefit from this research we will: (a) publish the results and present at conferences, (b) apply for funding to develop the ideas which pass the proof of principle phase and (c) make contacts with leading neural prosthesis design and manufacturing firms, such as MEDEL and Cochlear, to discuss the potential use of the techniques.


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Luan S (2014) Neuromodulation: present and emerging methods. in Frontiers in neuroengineering

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Nikolic K (2013) Drosophila Photo-transduction Simulator in Journal of Open Research Software

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Nikolic K (2010) A stochastic model of the single photon response in Drosophila photoreceptors. in Integrative biology : quantitative biosciences from nano to macro

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Nikolic K (2011) An Optical Modulator in Unmodified, Commercially Available CMOS Technology in IEEE Photonics Technology Letters

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Prodromakis T (2010) Switching mechanisms in microscale memristors in Electronics Letters

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Rapeaux A (2015) Fiber size-selective stimulation using action potential filtering for a peripheral nerve interface: A simulation study. in Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference

Description Summary

Study no.1. Bio-inspired signal transduction system.
(1) Completed a comprehensive biophysical model of the Drosophila phototransduction cascade, which provided new insights into the mechanisms of the single photon sensitivity and dark current/noise suppression of sensory cells signal transduction. (2) System design of the circuit architecture for a ultra sensitive vision chip. (3) A successful research proposal created which incorporated this idea: EU FP7 (Brain inspired - ICT): "SeeBetter". (4) Provided some crucial inputs for another EPSRC project (EP/G070466/1), proposing a new technique for detecting very weak optical signals buried deeply in the noise.

2. Memristors.
(1) Designed, fabricated and tested first memristive devices (the major objective). A fabrication method implementing the full active-material stack TiO2/TiO2+x with Ti/Pt electrodes, a single lithography and evaporation step. Experimental results confirm this method for fabricating memristors that exhibit consistent electrical characteristics. (2) A study into memristive networks which imitate a large number of synapses between neighbouring neurons, of various interconnection schemes, also an MSc project. (3) New proposal: "A beautiful mind: associative indexing and knowledge evolvement in memristive networks", EP/H050728/1, EPSRC ICT Brain-inspired (just below the line).

3. Combined opto-electrical neural stimulation.
(1) Major result: a continuous weak laser stimulation increases (not decreases as expected) the electrical stimulation threshold. This finding was confirmed by theoretical simulation in NEURON and COMSOL using FH model for myelinated sciatica nerve fibres. A comprehensive explanation for possible mechanism for this effect was developed (not to be released until being published).
(2) The selectivity of neural stimulation (activation of specific fibres in a big nerve) was achieved but indirectly, in the way of blocking AP generation. (3) Small funds were won from Imperial's internal call for funding in Strategic Neuroscience Initiative for the experimental setup.

4. Photosystem I (PSI) centre for neural stimulation.
The result of this study was negative, we were not able to identify pH change in our results, i.e. proton pumping action, using Photosystem I reconstituted in phospholipid vesicles and exposed to light. We discontinued this study and focused on more promising work on non-invasive stent blood-flow measurement system (not in original objectives). A platform for the prototyping, testing and trialing of non-invasive oximeter devices was developed. A working example device was demonstrated, which calculates total Haemoglobin, relevant as a non-invasive anaemia detector.

5. Stochastic resonance in central auditory system.
A pilot study was conducted on 20 subjects in acoustic anechoic chamber, noting down their gender, age group, first language, musical experience and hearing loss problems. The experiment involved playing noise in one ear and a speech signal in the other ear. The speech recognition threshold in noise (SRT) was measured, using the English Matrix Sentence Test. The correlation between the noise level and the total signal was established. The expected effect was found only for people with English as not their first language. Another outcome was that the SRT was higher on average for subjects for whom English was not their first language in comparison to those for whom it was. Further research is needed, in particular on subjects with cochlear implants to test for hearing improvements.
Exploitation Route Optoelectronic circuit designers and researchers benefited from our research and modelling of the enzymatic amplification cascade represented with its electronic equivalent. Mimicking the molecular biology amplifiers and signal transduction mechanisms in electronic circuits, lead to new types of circuit designs and contributed to the establishing of a new area of bio-inspired design called cytomorphic electronics.
Work on memristors or more precisely memristive devices is relevant for this nascent community in providing new ideas about how to design this type of devices and the instrumentation for their proper functioning. The area of nanoelectronics with ever decreasing feature sizes and increasing electronic chip functionalities is looking for new types of devices which can extend the "Moor's law" and memristors are one of the avenues.
Use of combined electro-optical stimulation demonstrated for the first time in this project that heating and temperature increase of neurons and axons can cause inhibition. This finding inspired a couple of groups to test it and they demonstrated the effect on several biological models. This has now opened new strategic paths in neural stimulation and neural prosthetic design (such as cochlear implant with IR laser for improved selectivity).
The use of noise to enhance sensory perception in human auditory pathways, is very much relevant for future studies of the role of stochastic resonance in human sensory pathways and perception.
Sectors Digital/Communication/Information Technologies (including Software),Healthcare,Pharmaceuticals and Medical Biotechnology

Description "Disruptive Semiconductor Technology for Advanced Healthcare Systems" (Platform Grant)
Amount £692,737 (GBP)
Funding ID EP/N002474/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 08/2015 
End 08/2020
Description European Commission (EC)
Amount £354,000 (GBP)
Funding ID Brain-Inspired ICT, Proj. No. 270324 
Organisation European Commission 
Sector Public
Country European Union (EU)
Start 02/2011 
End 04/2015
Description Imperial College Healthcare NHS Trust
Amount £250,000 (GBP)
Funding ID Biomedical Research Council 
Organisation Imperial College Healthcare NHS Trust 
Sector Hospitals
Country United Kingdom
Description Imperial College London
Amount £2,000 (GBP)
Funding ID Strategic Initiative in Neurotechnology 
Organisation Imperial College London 
Sector Academic/University
Country United Kingdom
Start 05/2010 
End 05/2010
Description Talk at Sutton Trust Summer School (6th form students with interest in EEE) entitled: \Microchips and Brain Implants", 4 August 2016. 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact 12 students enrolled on the "Sutton Trust" scheme attended a week long event at Imperial College EEE Department which involved various activities such as talks, lab sessions, tours, etc- which I gave a talk entitles "Microchips and Brain Implants".
Year(s) Of Engagement Activity 2016