Self-powered temperature sensors harnessing membrane potential of living cells

In this paper we present a novel method for remote temperature measurements of a bio-cell and its immediate surroundings, based on the use of electrical energy harvested from a single soleus muscle fiber. Our method employs an optimized RLC circuit, embedded with the cell, where the capacitor serves both as an energy storage unit and a temperature sensor, exploiting its natural temperature sensitivity. Once charged, the RLC oscillator emits a radio signal at a frequency that is dependent on the temperature. This signal can be received wirelessly through a receiver, facilitating remote temperature measurement. We present experimental tests performed on soleus muscle from mouse, where a maximum output voltage of - 70 mV is attained on a 1 mF capacitor. The experimental data confirm that our system can exploit the energy harvested from the cell membrane to communicate wirelessly the temperature and it can be employed in the range of biological interest (30 degrees C to 50 degrees C). Such self-powered temperature sensors have the potential to improve the field of biomedical sensing and non-invasive remote temperature monitoring.