Environmental IoT Applications & Agriculture: Low-Cost, Batteryless

Scatter Radio Sensors

Associate Prof. Aggelos Bletsas"aggelos@telecom.tuc.gr"

School of Electrical & Computer Engineering (ECE)

Technical Univ. of Crete, Chania, Greece

2nd Naftemporiki Technology

Conference, Internet of Things – Evolution in Action,

Divani Caravel, Athens " Dec. 8, 2016"

Problem: Networking all plants in a green-house/garden/field!"Why?"Ø  Water saving: precise irrigation

(80% of water potential => agriculture)"

Ø  Dense measurements => 30% water savings"

Ø  Plant health monitoring: precision agriculture."

“No-glue-technology” Challenge:"Ø  Reduce cost (in $$$ and Joules) of wireless networking:

from 75$-400$ => less than 1-5$/wireless sensor!"

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State-of-the-Art (2013) Commercial (French/Dutch) Technology..."

§  Humidity, temperature and sunlight to mobile (Bluetooth)."§  Problem: too expensive (what if 10000 plants?)!!!"

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Approach: Backscatter (Reflection/RADAR) Radio"

Ø Conventional Radio Transmitter:

filters, mixers, amplifiers…"

Ø  ~20mA (60mW), 100m – 1km

range."

Ø Backscatter/RFID Radio:

just 1 (transistor) switch!"

Ø …less than 0.6mA, “smaller”

range."

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TUC/Bletsas Group Scatter Sensor Networks Research Outcome:"

Ø  Range: 150+ m outdoors."

Ø  Cost: 3-10€/wireless sensor

in quantities of 1."

Ø  Power: Battery-less."

Ø  Network Size: 100+"5/8

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Example 1: Soil Moisture/Environmental Humidity Sensing"

Ø  Principle: convert capacitor changes to backscattered freq!"

Ø  Cost ~5€ (quantity of 1), Power ~100μWatt, RMS 1.9% SM. !Ø  Simple Networking (FDMA)."

Example 2: Plant = Sensor!"

Plant Electric Potential (EP) signal correlated..."

Ø  ...with solar irradiance,"

Ø  ...with plant watering! [IEEE Trans. Instrum. Meas., Feb. 2016]"7/8

Towards Commercial Exploitation"

Ø  Technology tested in real-world greenhouse conditions…"

Ø  …has attracted International Awards and Distinctions

(e.g., IEEE Sensors 13, IEEE ICASSP 15) "

Ø  Entrepreneurial Team ASTRAPI has been formed…"

Ø  …in the process of securing IP…"

Ø  …extensions to other markets/applications is also possible!

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