A low-power, low voltage autonomous single probe heat pulse soil moisture sensor based on semiconductors with energy harvesting using thermoelectric generators

• Grant number: 12/20862-4
• Support type: Scholarships in Brazil - Doctorate
• Effective date (Start): January 01, 2013
• Effective date (End): September 30, 2015
• Field of knowledge: Engineering - Electrical Engineering - Electrical, Magnetic and Electronic Measurements, Instrumentation
• Principal researcher: ELNATAN CHAGAS FERREIRA
• Grantee: Pedro Carvalhaes Dias
• Home Institution: Faculdade de Engenharia Elétrica e de Computação (FEEC). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated scholarship(s): 14/01470-3 - Design and fabrication of an autonomous heat pulse probe soil water moisture sensor using semiconductor devices fabricated with sprayed semiconductor ink on alumina, integrated with a bite thermoelectric generator, BE.EP.DR

Abstract

A novel soil moisture sensor based on the heat pulse technique, self-powered with an energy harvesting system will be developed. The sensor will employ a new technique, which uses only one junction transistor as both heating and temperature sensing elements. The soil moisture is obtained through the measurement of the temperature variation in the sensor caused by the heat pulse. In order to make the sensor useful for field applications, an ultra low-power wireless data communication system will be developed to transmit the data to a remote data-logger, which can process and present a georeferenced map of soil moisture data collected from each sensor. An energy harvesting system based on thermoelectric generators fabricated on flexible substrate will be developed and incorporated into the sensor. The energy harvesting system will use the temperature difference between the air and the sensor (which will be buried 20-30 cm into the soil) to generate all the energy required to make the sensor 100% autonomous, independent of any other energy supply. Due to the limitations of the energy supply of the harvesting system, it is necessary to design all electronics circuits of the sensing system with low-voltage and low-power techniques. The project shall contribute to the state-of-the-art of electronics soil moisture sensors in the following areas: - a new soil moisture sensor based on a single element (one bipolar transistor) will be developed; - an interrogation technique with low-power and low-voltage circuits will be developed for the new sensors; - a new sensor architecture and structure will be developed to allow that development of an energy harvesting system based on the temperature difference between the air and the sensor buried into the soil. - The energy harvesting system will be based on new thermoelectric generators fabricated in a flexible substrate, to be used in the proposed sensors structure. - a an ultra low-power and low-voltage wireless data transmission system will be developed, to be used with a georeferenced data-logger which will also be developed. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DIAS, PEDRO C.; CADAVID, DORIS; ORTEGA, SILVIA; RUIZ, ALEJANDRO; FRANCA, MARIA BERNADETE M.; MORAIS, FLAVIO J. O.; FERREIRA, ELNATAN C.; CABOT, ANDREU. Autonomous soil moisture sensor based on nanostructured thermosensitive resistors powered by an integrated thermoelectric generator. SENSORS AND ACTUATORS A-PHYSICAL, v. 239, p. 1-7, MAR 1 2016. Web of Science Citations: 11.

DIAS, PEDRO CARVALHAES; OLIVEIRA MORAIS, FLAVIO JOSE; DE MORAIS FRANCA, MARIA BERNADETE; FERREIRA, ELNATAN CHAGAS; CABOT, ANDREU; SIQUEIRA DIAS, JOSE A. Autonomous Multisensor System Powered by a Solar Thermoelectric Energy Harvester With Ultralow-Power Management Circuit. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, v. 64, n. 11, p. 2918-2925, NOV 2015. Web of Science Citations: 24.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

DIAS, Pedro Carvalhaes. Circuitos e componentes para Sensores Ambientais autônomos alimentados por módulos termoelétricos de energy harvesting. 2015. 102 f. Doctoral Thesis - Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Elétrica e de Computação Campinas, SP.