'Invisible' Solar Technologies from Bio-Inspired Optics

Lead Research Organisation: University of Exeter
Department Name: Engineering Computer Science and Maths

Abstract

Nature has optimised structures over billions of years through natural selection, a process which will forever exceed any 'trial and error' optimisation routine carried out by ourselves. Engineers can learn much from these achievements. The Cabbage white (Pieris brassicae) and Glasswing (Greta-Oto) butterflies have uniquely lightweight reflective and transparent wings which has been previously proven to be 17x lighter than current optical materials. Solar Concentrators (such as magnifying lenses designed for focusing the suns light) are a developing technology, which can utilise cheap glass or plastic optics to concentrate sunlight onto photovoltaic panels (these Concentrator photovoltaic systems are called CPV systems). These systems can reduce the amount of expensive heavily mined photovoltaic material required whilst maintaining the overall power output. CPV's can however be cumbersome, and so there lies a great opportunity to marry these disciplines of concentrator photovoltaics (optics+Solar panels) and natural lightweight structures (butterfly wing nanostructures) via biomimicry to gain significantly higher power-to-weight ratios for solar energy technology. Renewable energy, integrated into smart grids, buildings, vehicles and surrounding infrastructures, is an important pathway to reducing carbon emissions and advancing a sustainable lifestyle within society. This complex challenge demands interdisciplinary research and innovative design.

This fellowship aims to manufacture novel bio-inspired optics capable of at least tripling the power-to-weight ratio of concentrator solar energy technology. The surface structure of optics has significant effects on the light redirection and absorption. Micro-structured optics and coatings have shown rewards of increased power output and reliability for CPV devices but reduced weight designs require exploring. Fresnel lenses -an already lighter truncated version of convex lenses- only became popular with the discovery of lightweight poly(methylmethacrylate) (PMMA), making them more affordable and practical. This was a breakthrough for CPV in its very early years, and encourages further breakthroughs to entail new weight reduction methods matched to specific concentrator designs, as proposed here. This will be done on a nano, micro and macro level of engineering to obtain optimal performance and ensure outputs and impact. The production of high performing lightweight CPV panels which are more discreet than current PV panels and even invisibly integrated into buildings is the ultimate objective. This fellowship outlines theoretical and experimental methods, with strong focuses on materials and manufacturing characterisation aided by industrial collaboration and exploitation to credit the wide-spread impact of this pioneering research. Interdisciplinary research such as this will provide new solutions and understanding to firstly the disciplines of solar energy, optics, manufacturing, nanotechnology and biology but also branching off to incorporate the public perceptions of energy through collaborations with artists and companies to increase the impact of this research as well as showcasing and encouraging interdisciplinary research itself.
 
Title Butterfly Blueprints 
Description "Butterfly Blueprints", documentary film by Crescendo media films and aired by PBS NOVA. Explore how the scientific secrets of butterflies are inspiring technological innovations. The hidden scientific secrets of butterflies reveal them to be more inventive and resilient than we ever imagined. Follow their extraordinary life cycle and migrations to tropical rainforests, windswept prairies, and even inside a chrysalis as it's being spun. Discover how butterfly science is inspiring groundbreaking technology, including more efficient solar power cells, and bulletproof vests stronger than Kevlar. I advised on butterfly research alongside Prof. Richard Ffrench Constant. I gave a short interview that is featured in the film on applications from mimicking butterfly wings. 
Type Of Art Film/Video/Animation 
Year Produced 2022 
Impact This film has signifcantly increased my research profile and led to a few researchers, companies and memers of the public emailing me with inquires. I think this also led to an american company contacting me for consultancy work on a large green city project they are putting together. 
URL https://www.pbs.org/wgbh/nova/video/butterfly-blueprints/
 
Description Open Innovation Collaboration Fund with Bennamann Ltd on new types of Renewables systems for Cornish Farm, awarded by Exeter University
Amount £14,911 (GBP)
Organisation Higher Education Innovation Funding (HEIF) 
Sector Public
Country United Kingdom
Start 02/2022 
End 06/2022
 
Description Supergen Energy Networks Hub Flexible Funding: Feasibility study of coupling solar concentrators with photocatalytic technology for biomass photo-reforming to hydrogen and sustainable energy fuels.
Amount £3,460 (GBP)
Organisation University of Bristol 
Sector Academic/University
Country United Kingdom
Start 04/2021 
End 11/2022
 
Description Think Tank and Showcase: Research and Innovation for Net Zero Agriculture
Amount £3,300 (GBP)
Organisation Higher Education Innovation Funding (HEIF) 
Sector Public
Country United Kingdom
Start 01/2022 
End 06/2022
 
Description Dr Nathan Skillen - University of Belfast 
Organisation Queen's University Belfast
Country United Kingdom 
Sector Academic/University 
PI Contribution I was awarded the supergen Energy Network Flex funding to carry out a collaborative cross-hub feasibility project with Dr Nathan Skillen (Supergen Bioenergy Hub). I led the idea, management and application of the funding proposal and project once awarded. I provided time, optical modelling expertise, solar energy expertise, some small materials and equipment use (funded by award or already available in lab). This research project was exstended for a year (due to covid and Dr Nathan Skillen being awarded a temporary teaching role) and tied in nicely with my fellowship work as contributes to compact hydrogen generation and storage mechanisms, as well as a form of biomimicry (of photosynthesis) and developing my interdisciplinary research capabilities and profile. Without the EPSRC Fellowship, it may not have been possible for me to exstend this project and gain further research, results and networking from it.
Collaborator Contribution Dr Nathan Skillen provided expertise in bioenergy, hydrogen generation from photocatalysis, chemical suitability of biomass and photocatalyst materials. He provided his time and helped prepare the funding application. His time and some of his PhD students time was also contributed in preparing samples, carrying out measurements and analysising results. Dr Nathan Skillen was also awarded a 1 year Supergen Fellowship which i was a named collaborator on. Some of the funding for this award was used by Dr Nathan Skillen to visit the university of exeter where i am based to carry out experiments here. The project was exstended due to Covid travel limitations as well as Dr Nathan Skillen being awarded a temporary teaching role. At least 1 paper is under way from this research with likely further collaborations and grant bids to be made.
Impact At least 1 paper is under way and a grant proposal is planned which will incorporate some of my findings so far from my EPSRC Fellowship. The paper and proposal bid have been somewhat delayed due to Dr Nathan Skillen going on maternity leave.
Start Year 2021
 
Description Metamaterials Network - Led by Alastair Hibbens 
Organisation University of Exeter
Department School of Physics
Country United Kingdom 
Sector Academic/University 
PI Contribution Contributing expertise and contacts for sustainability themed applications of metamaterials, including inter-disciplinary and multi-disicplinary topics with collegues at the Environment and Sustainability Institute. Also provided industry contacts for CDT application.
Collaborator Contribution Included me in CDT discussions and potential to co-supervise Phd's. Allows me to expand my own network and profile to metamaterial themed researchers. Equipment and software use as well as reccomendations for specific functions have already been given and discussions had on potential collaboration projects. The sharing of some software (remotely accessed optical modelling software) is also taking place.
Impact CDT application Resource sharing Networking The collaboration is multidisciplinary, i will be bringing more multidisciplianry topics for discussion also.
Start Year 2022
 
Description Pittsburgh University Collaboration 
Organisation University of Pittsburgh
Country United States 
Sector Academic/University 
PI Contribution I have provided expertise, data and time for modelling, analysis and paper writting on Anti-reflection coatings for solar energy technology applications. Next step for this collaboration is to validate modelling results and expand glass etching method to concentrator optics. This will likely involve us applying for other funding.
Collaborator Contribution Prof. Paul Leu at Pittsburgh University and his team have developed a glass etching method that can achieve similar optical properties to the glasswing butterfly wing, which i am currently studying within my fellowship. Hence, they have provided the optical properties of their developed etched glass material which mimicks the glasswing properties.
Impact My work is interdisciplinary (Biomimicry - Biology and Engineering). Collaborator is Physics and Engineering based with also some biomimicry modelling.
Start Year 2022
 
Description Rising stars EDI event with Henry Royce Institute and MAINSTRAEM ECR's 
Organisation Henry Royce Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution Myself and other early career researchers Dr Jessica Wade (Imperial College London), Dr Alex Ramadan (Sheffield University) , Dr Lucy Whalley (Northumbria University) were brought together by Supersolar Supergen events and wanted to organise a series of events aimed at promoting EDI within solar energy related research communities. Jessica Wade and Alex Ramadan were successfull at applying for small funding from Roycal Society of Chemistry and Loreal to host an event at the Henry Royce Institute in Manchester. I also applied to the UKERC for further funding to host more events and an mentorship scheme but was unsuccessful.
Collaborator Contribution The Henry Royce Institute were excellent at providing their time, support and equipment leading up to the event and on the day of the event. They helped create and provided graphic design expertise for the website and workshop accessories (name badges and notpads). They also funded the catering for ~40 attendees. They are keen to host this even annually, and we have booked a provisional date in for next year which will be held at another location build the audience impact.
Impact Rising stars career development workshop aimed at promoting underrepresented groups within solar energy and materials research. Also provided small travel and caring grants to attendees to enhance accessibility, covering their costs to attend the event. 3 further £1k personal award grants were offered to applicants to aid their research career progression, the awarded projects were: Proper pipettes - funding for ergonomic pipettes that are easily used one handed Conference Travel - to help attend international conferences such as SPIE and META
Start Year 2022
 
Description Supergen - Falmouth University Science Media videos 
Organisation Falmouth University
Country United Kingdom 
Sector Academic/University 
PI Contribution My time, expertise and networking capabilities to connect 3 research scientists (including myself) with 3 media/illustration students at falmouth university to carry out a summer internship to make short media videos showcasing the ECR's research. Supergen contacted me first with the idea of creating the short videos. This was after i atteneded media training (part of my fellowship plan and a clear outcome). I then suggested and led the connection with Falmouth University who are based on the same campus as University of Exeter in Penryn.
Collaborator Contribution Christopher Malins from Supergen Supersolar provided his time and guidance in meetings as well as general schdeualing and admin to keep things going. Funding from Supergen Supersolar was provided to double the paid hours of the falmouth student interns on the project.
Impact 2 short media videos showcasing the state of the art research by myself and Dr Rachel Greenhalg at Loughborough University. A 3rd video is planned with Dr Sebastian Sprick at University of Belfast but so far there has not been a suitable artist intern. This has strengthened links with CREST at Loughborough and connections with the University of Belfast, as well as my own capabilities in creating creative outputs and transdisicplinary projects. I have expanded my network further towards creative practitioners and those at Falmouth University with strong scope to develop and continue this type of scheme where ECR scientists work with Art students to produce creative outputs and engagements.
Start Year 2022
 
Description Supergen - Falmouth University Science Media videos 
Organisation Loughborough University
Department Centre for Renewable Energy Systems Technology (CREST)
Country United Kingdom 
Sector Academic/University 
PI Contribution My time, expertise and networking capabilities to connect 3 research scientists (including myself) with 3 media/illustration students at falmouth university to carry out a summer internship to make short media videos showcasing the ECR's research. Supergen contacted me first with the idea of creating the short videos. This was after i atteneded media training (part of my fellowship plan and a clear outcome). I then suggested and led the connection with Falmouth University who are based on the same campus as University of Exeter in Penryn.
Collaborator Contribution Christopher Malins from Supergen Supersolar provided his time and guidance in meetings as well as general schdeualing and admin to keep things going. Funding from Supergen Supersolar was provided to double the paid hours of the falmouth student interns on the project.
Impact 2 short media videos showcasing the state of the art research by myself and Dr Rachel Greenhalg at Loughborough University. A 3rd video is planned with Dr Sebastian Sprick at University of Belfast but so far there has not been a suitable artist intern. This has strengthened links with CREST at Loughborough and connections with the University of Belfast, as well as my own capabilities in creating creative outputs and transdisicplinary projects. I have expanded my network further towards creative practitioners and those at Falmouth University with strong scope to develop and continue this type of scheme where ECR scientists work with Art students to produce creative outputs and engagements.
Start Year 2022
 
Description Art and Energy - Board of Directors 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I am on the board of directors for Art and Energy and have helped them transition to a charity status which allows them to expand the types of funding and activities they can carry out for communities and buisnesses. With the other members of the baord i habe helped guide them to create a combination of workshops and events targetted at 1)buisnesses and 2)communities, both aimed at increasing sustainability. Art and Energy regularly hold various types of exhibitions, workshops and events for schools, companies, communities, online media platforms and policymakers (e.g. exhibition at COP26 ).
Year(s) Of Engagement Activity 2022
URL https://www.artandenergy.org/
 
Description Creative Exchange Organiser (repeated meetings, exhibitions and some workshop events) 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact The Creative Exchange Programme facilitates collaboration between creative researchers on our Cornwall Campuses who share an interest in issues of environment and sustainability. The programme inspires new research relationships and stimulates opportunities for public engagement and collaborative learning. We work closely with University of Exeter Arts & Culture and other initiatives that seek to develop the region's creative industries.

I have been asked to be one of the organisers going forward as i have also particpiated in and continue to do creative exchange collaboraitons with artists (Art and Energy and UCG) which produced solar panel artworks ein the past.
So far this as involved 2 worksops with researchers (from all disciplines and mainly ECRs) and judging and awarding small pots of funding to artist-scientist collaborations to produce exhibitions of state of the art research from different perspectives. This often leads to very interesting interdisciplinary discussions and impacts researchers opinions on best research practice. The exhibitions are on show for any and all visitors which often include school visits, scientists, artists, policymakers and industry professionals.
Year(s) Of Engagement Activity 2022,2023
URL https://www.exeter.ac.uk/research/esi/community/creativeexchange/
 
Description Online moths watch and biomimicry presentation for general public and children 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact with support from Art and Energy (Project partners) we hosted a series of online talks, workshops and events focusing on moths and butterflies. This often included an evening session with presentations from researchers and moth and butterfly enthusiasts from across the UK and then a morning session where people from across the UK with moth traps would show what moths they got in their traps that morning.

At the end of this project (final wrap up sessions/events in early 2022), I presented and discussed my biomimicry research so far into the cabbage white butterfly, the glasswing butterfly and moth eye anti-reflective structures and how we can copy these natural nanostructures for our own optics and technologies for solar energy.
Year(s) Of Engagement Activity 2022
URL https://www.mothstoaflame.art/
 
Description Truro Highschool GreenPower Racecar 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Truro Highschool for girls annually takes part in the aspirational Greenpower racing event in Cornwall. This event helps to inspire thousands of school students into engineering education. The exciting event, held annually at Predannack Airfield near Mullion, sees school teams from across the south west designing, building and racing electric powered cars, gaining a unique and hands-on experience of real world engineering applications.

I helped the students design their racecar by being their CAD drawing expert, all other technical aspects of the racecar design and the parameters and material decisions were decided by them. I visited Turo highschool and had online teams meeting with the students to help teach them how to use solidworks CAD and to help measure and finalise their components which would be ordered or cut at other companies.

The students also won the national competition due to their short video they made, winning the change to work with a real racecar driver to help prep them for the international finals. This activity is a unique hand on experience for the girls into an example of exciting eingeering work.
Year(s) Of Engagement Activity 2022
URL https://www.facebook.com/watch/?v=1024266398411401
 
Description Upcycled Glass Company - Board of Directors 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact I am on the board of directors for the upcycled glass company and meet regularly with the other directors to discuss best next steps for UGC.
Year(s) Of Engagement Activity 2022