3D Printing Soft Robotic Grippers for Automated Strawberry Harvesting

Strawberries are the second most produced and highest value fruit in England with 141,600 tons grown annually fetching £2,460 per ton. However, strawberries are very labour-intensive to harvest, which increases costs and vulnerability to labour shortages. Even before the pandemic there was an over 30% shortage of pickers in the UK, causing tons of fruit and vegetables to be lost.[2] This has motivated much research into automated picking technologies, typically using pneumatic or hydraulic grippers. However, the rigid materials (often metals) these are made from make existing grippers prone to damaging strawberries.[3][4][5] Soft robotics is a new field aiming to make robots consisting largely of soft materials.[6] 3D printing allows the manufacture of novel soft robots that can mimic the complexity and functionality of biological organisms, enabling new strategies to enhance robot performance. This project aims to investigate a novel 3D printed soft robotic gripper solution enabling rapid yet gentle harvesting of strawberries. This will use new kinds of 3D printers being developed in the supervisor's group. It will also explore new materials and structures. Together, these new technologies will lead to a solution of more suitable robotic grippers and potentially a step change in the performance of robotic harvesting.

References [1] GOV.UK, "UK HORTICULTURAL STATISTICS.",GOV.UK,(ACCESSED DEC. 2020).[2] https://www.theguardian.com/business/2020/may/20/farms-still-need-up-to-40000-uk-workers-to-harvest-fruit-and-veg (ACESSED JAN. 2021)[3] M. MLOTEK, L. KUTA, R. STOPA, P. KOMARNICKI. "THE EFFECT OF MANUAL HARVESTING OF FRUIT ON THE HEALTH OF WORKERS AND THE QUALITY OF THE OBTAINED PRODUCE," PROCEDIA MANUFACTURING 3, 2015.[4] M. Garrad, G. Soter, A. T. Conn, H. Hauser, J. Rossiter. "A soft matter computer for soft robots", Science Robotics, 4, 33, 2019.[5] Y.Xiong, C.Peng, L.Grimstad, P.J.From, V.Isler. "Development and field evaluation of a strawberry harvesting robot with a cable-driven gripper", Computers and Electronics 157, 392, 2019.[6] T. Wallin , J. Pikul, R. F. Shepherd, "3D printing of soft robotic systems.", Nature Reviews Materials, 3, 84, 2018.

The proposed CDT provides a unique vision of advanced RAS technologies embedded throughout the food supply chain, training the next generation of specialists and leaders in agri-food robotics and providing the underpinning research for the next generation of food production systems. These systems in turn will support the sustainable intensification of food production, the national agri-food industry, the environment, food quality and health.

RAS technologies are transforming global industries, creating new business opportunities and driving productivity across multiple sectors. The Agri-Food sector is the largest manufacturing sector of the UK and global economy. The UK food chain has a GVA of £108bn and employs 3.6m people. It is fundamentally challenged by global population growth, demographic changes, political pressures affecting migration and environmental impacts. In addition, agriculture has the lowest productivity of all industrial sectors (ONS, 2017). However, many RAS technologies are in their infancy - developing them within the agri-food sector will deliver impact but also provide a challenging environment that will significantly push the state of art in the underpinning RAS science. Although the opportunity for RAS is widely acknowledged, a shortage of trained engineers and specialists has limited the delivery of impact. This directly addresses this need and will produce the largest global cohort of RAS specialists in Agri-Food.

The impacts are multiple and include;

1) Impact on RAS technology. The Agri-Food sector provides an ideal test bed to develop multiple technologies that will have application in many industrial sectors and research domains. These include new approaches to autonomy and navigation in field environments; complex picking, grasping and manipulation; and novel applications of machine learning and AI in critical and essential sectors of the world economy.

2) Economic Impact. In the UK alone the Made Smarter Review (2017) estimates that automation and RAS will create £183bn of GVA over the next decade, £58bn of which from increased technology exports and reshoring of manufacturing. Expected impacts within Agri-Food are demonstrated by the £3.0M of industry support including the world largest agricultural engineering company (John Deere), the multinational Syngenta, one of the world's largest robotics manufacturers (ABB), the UK's largest farming company owned by James Dyson (one of the largest private investors in robotics), the UK's largest salads and fruit producer plus multiple SME RAS companies. These partners recognise the potential and need for RAS (see NFU and IAgrE Letters of Support).

3) Societal impact. Following the EU referendum, there is significant uncertainty that seasonal labour employed in the sector will be available going forwards, while the demographics of an aging population further limits the supply of manual labour. We see robotic automation as a means of performing onerous and difficult jobs in adverse environments, while advancing the UK skills base, enabling human jobs to move up the value chain and attracting skilled workers and graduates to Agri-Food.

4) Diversity impact. Gender under-representation is also a concern across the computer science, engineering and technology sectors, with only 15% of undergraduates being female. Through engagement with the EPSRC ASPIRE (Advanced Strategic Platform for Inclusive Research Environments) programme, AgriFoRwArdS will become an exemplar CDT with an EDI impact framework that is transferable to other CDTs.

5) Environmental Impact. The Agri-food sector uses 13% of UK carbon emissions and 70% of fresh water, while diffuse pollution from fertilisers and pesticides creates environmental damage. RAS technology, such as robotic weeders and field robots with advanced sensors, will enable a paradigm shift in precision agriculture that will sustainably intensify production while minimising environmental impacts.