To better understand how threats such as climate change, habitat loss and the illegal wildlife trade are driving species to extinction, conservation technology can play a critical role in helping to monitor, assess and collect valuable data to inform policy and take action.

Environmental sensors and camera traps play a pivotal role in helping us to understand change over time and are regularly deployed as part of species monitoring and protection activities. Batteries and/or classical solar panels (e.g., PV) frequently used to power those devices are not always ideal: the first requires manually replacing batteries overtime to recharge them, the second requires adequate sunlight to operate. When deployed beneath dense canopies or shrouded by mist in cloud forests, sunlight can be limited.

To address these issues, the Arribada Initiative in unison with OpenPlant would like to power environmental sensors using plant-BES (bio electrochemical system) solutions. This challenge opens up access for architects, engineers, designers or scientists to do just so by providing the necessary funding (£10,000) required for prototying materials and associated costs.

Can you design and manufacture a prototype open source plant-BES (bio electrochemical system) to power a camera trap and environmental sensors in tropical forests?

The aim of this challenge & further information

• Design and construct four identical prototypes of plant-BES systems to power a camera trap in the Peruvian Amazon rainforest.
• Each prototype should be able to deliver 5V and produce 5000mC of charge per day. We have taken into consideration the energy consumption due to the use of a capacitor too. See further down for more considerations about predicted energy consumption scenarios and how to achieve 5V of power.
• The camera trap / sensor board has been provided by Icoteq and will be optimized to consume a stand by current of 20uA. The board (ICO-TJSB-500) supports Micro Python and will automatically wake and take a photograph, you only need to provide the power source and mount the board within your prototype.
• Three prototypes of plant-BES systems will be delivered to the Peruvian Amazon forest and should operate using local vascular plants and soil. The use of local shade-loving vegetation and soil should be used to avoid the introduction of non-native species and to minimize the weight. We hope to test a fourth prototype in the tropical greenhouse at ZSL London Zoo (UK). The design will need to be robust and lightweight - max 5kg per prototype (that’s its dry weight, i.e without plants and soil).
• Each prototype needs to have a waterproof case to incorporate the camera trap (sensor board) and any necessary electronic components. The complete technical details are available for you to review. The sensor board is 50mm x 50mm in size.
• The prototypes need to have dimensions conducive to being carried in a rucksack, or an ability to be packed down into one so it can be carried into the field in the future for deployment.
• The prototypes should be designed to support plant growth and longevity (for about 1 year) in a rainforest area. Based on the World Climate Guide, the monthly average rainfall at our target site is 240±58 L per square meter, with 16±2 days of rain per month (see table 1). The temperature is expected to vary from a minimum of 21°C to a maximum of 32°C (see table 2).
• All designs should be CERN OHL v.1.2. licensed to ensure that they can be freely accessed and used by anyone wishing to manufacture their own, or wishing to enhance the design further. We do not have any interest to commercialise the prototypes.
• We will be awarded £10,000 if successful to cover all material costs for the production and manufacture of four prototypes. No additional funding will be available. To be eligible to apply you should be affiliated to a registered organization (e.g., University, Research Centre, etc.), or if you are an individual, you should contact us and we will review your submission on a case-by-case basis. You will receive 50% of the funds in advance and the remaining funds on delivery of the four prototypes.

Each prototype should be able to deliver 5V and produce 5000mC of charge per day.

Registering for entry

You can register for entry at http://arribada.org/plant-powered/view.php?id=10182

Please provide:

• Name/surname and affiliation of the main applicant.

• Name/surname and affiliation of the co-applicant(s)

• Complete details of the registering organization.

• Academic or industrial relevance with this project  

• A detailed technical drawing of the prototype plant-BES system (materials, dimensions, etc.). Please submit your drawing so it is viewable in FreeCAD (.Fcstd) or a format supported by FreeCAD. If you cannot submit a CAD drawing, we are happy to accept alternatives that you feel demonstate the concept.

Any proposals that are not selected will be returned to the owners and your submission kept private.

If shortlisted, we will contact you for more information. 

Timetable

• Submit your proposal before midnight on the 30^th April 2018 (GMT).
• During the second week of May 2018 we will select shortlisted projects.
• At the end of May 2018 we will contact the shortlisted teams and will pick the winning proposal.
• The time necessary to construct the prototypes will be negotiated with the shortlisted team during the second half of May 2018.

We will cover all material costs for the production and manufacture of four prototypes up to £10,000.

Is the aim of this project achievable?

The required potential (5V) and current (5000mC per day) to power the camera trap as declared is deemed to be feasible.

Taking into consideration the results published on plant-BES systems operated outdoors with vascular plants (Table 3). the data available states that the average current density observed at peak power was ~100 mA m-2, ranging from 17 to 400 mA m-2, and the average potential observed at peak power was ~283 mV, ranging from 200 to 400 mV.

By adopting a conservative approach, we decided to base our estimation on the lower of the reported values: 17 mA m-2 and 200 mV. Based on this data, to achieve the required potential of 5V, the system needs to comprise of a minimum of 25 plant units (5V / 0.2V = 25) connected in series. To achieve the required current of 5000mC per day, each unit forming the system needs to have a minimum surface area of (0.03mA / 17 mA m-2) ~35.3 cm2.

Therefore, by including in each system a minimum of 25 units, each with a total surface area of at least (35.3 cm2 x 25) ~883 cm2, in principle the aim of this project is achievable.
 
As no experimental data is available for plant-BES systems operated in a tropical forest with local plants for a long period of time, a prudent approach would suggest to increase the number of units and the surface area as much as the physical constrains of this project permit. In other words, the number of units and the surface area need to be increased as much as possible without exceeding the permitted mass (5 kg per unit) and the permitted volume (to be packed down into a rucksack).

Table 1 (below). Average rain precipitation recorded in the Peruvian Amazonian forest (la Selva). https://www.climatestotravel.com/climate/peru

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Average	St Dv
Prec (L m2)	255	275	350	305	270	200	165	155	190	215	245	255	240	58
Days	17	18	20	19	18	15	14	12	14	16	17	16	16	2

Table 2 (below). Average temperature recorded in the Peruvian Amazonian forest (la Selva). https://www.climatestotravel.com/climate/peru

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dev	Average	St Dv
Min C	22	22	22	22	22	22	21	21	21	22	22	22	22	0
Max C	31	32	31	31	30	30	30	31	32	32	32	31	31	1

Table 3 (below). Results published on plant-BES systems operated outdoor with vascular plants

Reference	Vascular Plant	mW m2	mA m2	mV
10.1016/j.biortech.2015.03.014	T. latifolia	6.1	17	360
10.1016/j.biortech.2012.08.020	P. setaceum	163	400	400
10.1016/j.wasman.2014.11.004	O. sativa	23	115	200
10.1271/journal.pone.0077443	O. sativa	14.4	72	200
10.1371/j.biortech.2015.05.098	O. sativa	19	63	300
10.1016/j.biortech.2015.03.014	C. indica	18	75	200
10.1155/2013/172010	I. aquatica	12	30	400
10.1007/s00253-008-1410-9	O. sativa	6	30	200

(note - visit http://www.doi.org/index.html and enter the DIO reference numbers above to access the relevant papers).