Vertical farming is the practice of growing plants, indoors, under controlled conditions in stacked layers, often without solar light. Hydroponics is a subcategory of vertical farming, where the roots are submerged in water containing nutrients for growth. Benefits of such a system include reduced water consumption and higher yields when compared to conventional farming, as well as enabling local growing throughout the year. Indoor growing is also resilient to extreme weather, can make use of brownfield sites and provide access to cultivation in households with limited access to outdoor space.

There is a growing interest in automation, robotics and internet of things (IoT) to enable farmers to monitor the hydroponic environment, with AI increasingly being used to optimise growing systems for higher quality produce. Robots are more able to move around the tall vertical systems than humans, improving space efficiency and administering plant care such as imaging and picking.

What did the project involve? 

Robotany was a multidisciplinary project that brought together engineers, artists and hydroponic growers to explore the use of recent robotics innovations from the University of Bristol as a means to advance automation of vertical farming. The work seeks to develop demonstrators exploring bacteria-powered robots, bio-hybrid and bio-inspired sensing, and creative audio-visual communication modalities, in a new context: increasing the viability of hydroponics as a transformative food production solution for sustainable growing in the face of the climate crisis.

The project was a partnership between an artist and hydroponic grower and artist, roboticists, and a sound and technology artist to explore recent research innovations at the Bristol Robotics Lab (BRL) and Rachel Nee’s CERN residency. The project sought to address key challenges in hydroponics growing, to make a significant contribution to the viability of this technology for ensuring food security in the face of the climate crisis.

A challenge with hydroponics is a potential increased energy consumption when compared to conventional farming. Prior to this project, Hemma Philamore had developed self-powered swimming robots that harvest energy for locomotion from organic matter in the surrounding water (Fig a). Elliott Scott had developed a novel bio-inspired sensor that replicates the behaviour of lateral line sensing in fish to detect turbulence of the water (Fig b). And Rachel Nee had produced art-works such as a potato-powered amplifier (Fig c)

The researchers sought to investigate the impact of this work in a new application by quantifying the energy that can be harvested (light and biomass) in a small-scale hydroponic system and using this to power a self-powered mobile robot and a self-powered sound installation to communicate system health. They also aimed to evaluate turbulence sensors and Microbial Fuel Cells combined with machine learning for predicting the nutrient content and distribution of the water.

The research team set out 3 primary aims:

Aim 1: Develop self-powered robots and sensing demonstrators. 

• Quantify the electrical output and harvestable energy using different energy harvesting technologies (microbial fuel cells, photovoltaic cells (PVCs)).
• Create a mapping between MFC and turbulence sensor data and nutrient levels recorded through lab tests using machine learning. Test the prediction
  accuracy of the system.
• Build a prototype energy-autonomous mobile robot based on the established energy budget.

Aim 2: Develop a relatable interface to communicate the status of the environment within the hydroponic system to growers.

• Power amplifier using harvested energy from MFCs and PVCs.
• Test feasibility of powering different technologies for sound from harvested
  energy; analog synth, microcontroller or microprocessor.
• Use data from sensors to experiment with sound and visuals that will provide an accessible, engaging diagnosis of system health for the grower.

Aim 3: Engage local industry and community in future of Robotany.

• Offer a presentation of the outcomes of the work to local vertical-farming businesses and gain feedback and engage support of furthering the work such as industrial partnerships and equipment contributions.
• Run a drop-in, introductory session with local school children/families.

Who are the team and what do they bring?

• Hemma Philamore (Engineering Mathematics, University of Bristol) is a researcher with a focus in robotics and autonomous systems. She specializes in soft, energy-autonomous and bio-hybrid robots–including microbial and protein-based systems for electrical power generation and sensing.
• Elliott Scott (Engineering Mathematics, University of Bristol) is a postdoctoral researcher with a background in aerospace engineering and bio-inspired sensors.
• Katy Connor (Spike Island) is an artist and hydroponic grower who explores how bodies and experiences are reconfigured within biotechnological environments. She frequently collaborates with artists, academics and scientists: responding to laboratory research at Plymouth, Exeter and Bristol Universities and travelling to remote places, including the High Arctic. Recent co-authored articles were published in Interdisciplinary Science Reviews and NanoEthics (2020). Katy’s studio is based at Spike Island, an international centre for contemporary art in Bristol.
• Rachel Nee is an experienced professional artist, making and selling art, curating shows and teaching workshops. She has a particular interest in the interface between art and science. She is especially drawn to physics. She enjoys exploring themes such as; energy, entropy, scale, time and matter.

What were the results?

The outcomes of this work provided a proof-of-concept demonstration of robots that can operate energy-autonomously within hydroponics systems, re-using waste products from plants and removing the need for refueling by human operators. The project also made a significant contribution to the current state of the art in sensing nutrient level and regulating distribution of oxygen and nutrients. This will potentially make care of hydroponic systems easier to manage both at farm and domestic scale making hydroponics a more promising solution for food security during the climate crisis.