Energy harvesting device and energy harvesting system

An energy harvesting device configured to convert thermal energy into electrical energy, comprising:

• a heat storage portion having an insulating property and configured to store thermal energy;
• a thermoelectric element:
• disposed on the heat storage portion in an upward direction of the energy harvesting device,
• including:
• a first electrode;
• a second electrode, having a work function different from a work function of the first electrode, disposed above the first electrode in the upward direction;
• and
• an intermediate portion disposed between the first electrode and the second electrode, and
• configured to eliminate a temperature difference between the first electrode and the second electrode when converting thermal energy into electrical energy;
• and
• an insulating portion disposed on the heat storage portion in the upward direction and covering the thermoelectric element to contact an upper surface of the thermoelectric element and side walls of the thermoelectric element, wherein
• the intermediate portion includes a solid insulating layer in which nanoparticles are fixed in a dispersed state.