A new low-complexity paradigm for analogue computation and hardware learning

Lead Research Organisation: University of Surrey
Department Name: ATI Electronics

Abstract

The Fellow and his team are seeking to develop a ground-breaking electronic device named the multimodal transistor. Arising from more than a decade of experience in unconventional device design, it allows for entirely new applications such as hardware learning, analog computation and control, while being energy efficient and easy to fabricate.

News headlines in electronic devices usually hail developments in nanoscale billion-transistor chips, yet there are major opportunities for innovation in display screen technologies, in which the requirement of fabricating circuits at low cost over large areas, and not ultimate miniaturization, is prevalent. Existing fabrication facilities are now partly being repurposed for emerging large area electronic (LAE) applications: microfluidics, lab-on-a chip, ubiquitous sensors or wearable electronics. LAE usually contain large arrays of relatively simple circuits with few transistors, as areal performance variations impede the fabrication of complex circuits. Incremental progress in LAE is constantly achieved through processes and equipment improvements, and by using new materials with superior properties, both with large capital investment.

The Fellow proposes a major step in LAE development, a radical new device design: the multimodal transistor (MMT). The MMT enables new ways of designing electronic circuits for efficient analog operations (amplification, data conversion, analog computation), control and feedback, and ultimately, LAE circuits capable of learning (hardware AI), so far impractical with conventional devices and techniques. Functionality is achieved using energy-efficient circuits of minimal complexity, allowing environmentally friendly fabrication at low cost. By greatly expanding the design possibilities, while being entirely compatible with conventional LAE fabrication, MMT circuits extend the usable lifetime of current manufacturing technologies, maximising the return on investment, and can accelerate the uptake of emerging processes such as 2D semiconductors and spatial atomic layer deposition.
The Fellow's team will leverage our long experience in device design and the complementary capabilities of our international partners to design, fabricate and test devices and circuits using vacuum processing and additive manufacturing in conventional and emergent semiconductor systems, supported by state-of-the-art numerical simulation. The team will use their extensive collaborator networks to seed the development of a new electronic design paradigm.

As this is an enabling technology, its applications span fields from disposable medical diagnostics and crop monitoring to autonomous vehicle control, new forms user interfaces and immersive entertainment environments, with substantial long term economical and public benefits for the UK and the world. The implications of the novel functionality, such as hardware AI and autonomy, will be a constantly considered. Stakeholders will be involved in shaping the research through cross-disciplinary workshops, online engagement and science festival participation. The focus on people will further include: continuing a decade-long tradition of training, mentoring and involving school students in the Fellow's research; supporting a strong start to the careers of young researchers involved through mentoring, independence and due to the ground-breaking nature of the work; and incorporating the findings into Surrey's teaching curriculum to increase our graduates' employability.

The Fellowship will accelerate the Fellow's growth as an international technical and thought leader, while retaining valuable skills, intellectual property and know-how in the UK at a time of global uncertainty. A Fellowship is the optimal funding route, allowing full commitment to advancing this trailblazing design paradigm, within a robust structure and collaborative environment which includes world-leading research facilities and support networks.

Planned Impact

The proposed versatile electronic device is an enabling technology with numerous uses. Its introduction will broaden the scope of applications for existing technologies, reducing complexity and improving manufacturability; in the long term it provides a new, disruptive framework for computation using minimal device count and ultra-low-cost fabrication, as a complementary development to emerging beyond-Moore nanoscale digital circuits and quantum computers. Arising from the project will be valuable, broad IP, energy efficient technologies and highly trained scientists and engineers.

In the short and medium term, deploying the device as a replacement for complex electronic circuits made with existing technologies would readily result in lower-cost display screens with superior uniformity and aging characteristics. The recent stagnation in conventional display industry profitability (2.4% CAGR, DSCC report, IMID2019) would be overcome through yield increases and a move to higher resolutions without major changes in processes or materials. The same platform, including emerging flexible screen technology, can produce low-cost, high-value solutions for new applications of wide societal and economic benefit. The multimodal transistor's key attributes circumvent many current limitations and will lead to ubiquitous sensors with in-built processing and decision (e.g. for disposable medical diagnostics, agricultural monitoring, smart packaging, etc., industries which collectively are expected to be worth >$60Bn by 2030 globally). Through superior device behaviour and functionality, this will concurrently broaden the output of existing manufacturing facilities and accelerate new technology and material systems uptake, with important economic implications.

In the long term, the largest value of this unconventional design approach is as a new means of performing efficient computation, decision and learning in hardware, with a minimal number of devices and using low-cost fabrication processes. A large variety of efficient autonomous systems, many entirely unforeseen at present, are likely to stem from this enabling technology, with wide-reaching societal and economic implications and directly applicable to the interests of project partners: from new applications of simulation tools and optimised fabrication processes to novel electronic platforms and areas of scientific endeavour. Consideration is given to the ethical and human aspects from the beginning, involving specialists in these areas as well as diverse stakeholders through collaborators' networks and non-technical interest groups (see Pathways to Impact).

The "People at the Heart of ICT" EPSRC priority is further addressed through the training and career opportunities for the early career researchers and students. Unique technical training through working on a major new concept, and ample opportunity for networking or secondment, create a strong foundation for successful careers. The project's length provides job stability for the postdoctoral researchers, as we transition through considerable worldwide uncertainty. New science will be readily introduced into the undergraduate and MSc curriculum at the host institution, ensuring world-leading multidisciplinary training for future specialists. Children of all ages will be introduced to the prospects of STEM careers by building on the inclusive culture of school and community outreach central to the Fellow's activities.

The fellowship will serve as a means of building critical mass in an emerging area, supporting the growth of the Fellow into an international thought leader. Building on past national investment, leveraging EPSRC-supported facilities, and expanding the worldwide recognition of current research activities, the Fellow's growing scientific influence will be utilised to champion UK research excellence, strengthen national science policy and foster new strategic collaboration.

Publications

10 25 50
 
Description We are investigating a new type of electronic device which can perform the function of several conventional devices, for improved control, energy efficiency and utilisation of available area. Thus far, we have demonstrated that such devices (multimodal transistors) can be applied efficiently to digital-to-analog conversion, display pixel driving via pulse width modulation, digital logic, analog signal mixing and neural network hardware for signal classification. This gives confidence in the robustness and the practicality of the initial idea. The next step, currently under development, is to demonstrate tolerance to manufacturing variability and suitability to industrially practical fabrication processes. A continuous background activity is the development of a toolkit of electronic circuits which take avantage of the multimodal transistors' unique features and which can be mixed and matched to improve the reliability, signal quality and energy efficiency of a variety of applications in wearable and distributed sensors.
Exploitation Route The projects aims to generate a set of electronic devices and circuits which act as building blocks and initial components of a vast range of electronic applications. Various facets of the concept are more suited to different fabrication techniques and materials. For this reason, several groups worldwide are investigating means of reliable realisation of these ideas using their specialist processes. This includes development of numerical models which are essential for design automation and integration with commercial fabrication processes.
Sectors Agriculture

Food and Drink

Education

Electronics

Environment

Healthcare

Leisure Activities

including Sports

Recreation and Tourism

Manufacturing

including Industrial Biotechology

Retail

 
Description Cambridge 
Organisation University of Cambridge
Country United Kingdom 
Sector Academic/University 
PI Contribution Device and circuit design and characterization
Collaborator Contribution Device fabrication, material characterization
Impact 4 journal papers with joint authorship.
Start Year 2017
 
Description Gachon 
Organisation Gachon University
Country Korea, Republic of 
Sector Academic/University 
PI Contribution Device design and optimisation, data analysis and interpretation.
Collaborator Contribution Fabrication and characterisation.
Impact https://doi.org/10.1021/acsami.2c22350
Start Year 2022
 
Description Max Planck Institute 
Organisation Max Planck Society
Department Max Planck Institute for Solid State Research
Country Germany 
Sector Academic/University 
PI Contribution We devised new electronic device structures, tested the fabricated samples and analysed data.
Collaborator Contribution The MPI team fabricated devices according to our specifications.
Impact https://doi.org/10.1002/aelm.202101101 https://doi.org/10.1002/aelm.202201163
Start Year 2021
 
Description NAIST 
Organisation Nara Institute of Science and Technology
Country Japan 
Sector Academic/University 
PI Contribution Device design, simulation, data analysis and interpretation
Collaborator Contribution Fabrication, simulation, measurements
Impact n/a
Start Year 2023
 
Description University of Kentucky 
Organisation University of Kentucky
Country United States 
Sector Academic/University 
PI Contribution Co-design of organic multi-modal transistors
Collaborator Contribution Fabrication of organic multi-modal transistors
Impact engineering, chemistry and material science
Start Year 2021
 
Description Wollongong 
Organisation University of Wollongong
Country Australia 
Sector Academic/University 
PI Contribution We are specifying the technical requirements, designing and testing the hardware, developing the software and user interfaces, developing the physical packaging.
Collaborator Contribution The Wollongong team are specifying the user requirements and will be running the testing and trials of the technology
Impact We are developing miniaturised wearables for use in movement studies with young children.
Start Year 2022
 
Title APPARATUS FOR PRODUCING AN ELECTRICAL SIGNAL THAT IS INDICATIVE OF A TEMPERATURE 
Description Apparatus for producing an electrical signal that is indicative of a temperature is disclosed, the apparatus comprising: a first thin-film transistor TFT comprising a first source, a first gate and a first drain, the first drain being configured to receive a reference current; and a second TFT comprising a second source, a second gate and a second drain, the first and second gates both being configured to receive the same gate voltage, wherein the first and second TFTs are configured such that a temperature dependence of the first TFT differs from a temperature dependence of the second TFT, such that an output current at the second TFT and the second drain is dependent on temperature. The temperature dependence of the output current can be controlled by selecting suitable design parameters for the first and second TFTs. A method of designing the apparatus to produce an output current with a target temperature dependence is also disclosed. 
IP Reference WO2021038230 
Protection Patent application published
Year Protection Granted 2021
Licensed No
Impact n/a
 
Description ATI 20th anniversary 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Our research institute celebrated 20 years of activity. I gave a talk summarising the legacy and perspective of flexible and printed electronics activities, with a focus on the broad range of potential applications of these enabling technologies. 100+ attendees included global academic and industrial experts.
Year(s) Of Engagement Activity 2022
 
Description Futurum Magazine 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Dr Radu Sporea was featured in Futurum Magazine, including a career profile and an activity sheet for schools. The magazine usually reaches tens of thousands of downloads worldwide.
Year(s) Of Engagement Activity 2022
URL https://futurumcareers.com/Radu-Sporea-Activity.pdf
 
Description Press releases 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Research papers on applications of multimodal transistors to neural networks and on increasing energy efficiency of multimodal transistors by device-circuit interaction have been accompanied by press releases from the host university. Numerous online science/enginering outlets have run the stories, exposing a large general audience to our work, raising awareness of the general area of emerging electronics.

e.g. https://www.azom.com/news.aspx?newsID=56686,
https://www.technologynetworks.com/informatics/news/multimodal-transistor-successfully-demonstrated-in-artificial-neural-networks-357662
Year(s) Of Engagement Activity 2021,2022
URL https://www.technologynetworks.com/informatics/news/multimodal-transistor-successfully-demonstrated-...
 
Description School Visit - Oxford 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact A careers day talk at St Clares School in Oxford, attended by ~20 pupils, challenging them to consider how the varied science subjects they study find their ways into advanced electronic device engineering, with many reporting that they are more likely to consider engineering degress as a result.
Year(s) Of Engagement Activity 2022