A high temperature downhole power generating device includes a power generator including a first material of one polarity and a second material that is fixed in position and is of opposite polarity of the first material, wherein the first material is propelled toward the second material based on motion of the high temperature downhole power generating device so that the two materials have a maximized point of contact to generate maximum power, at least one electrode that is connected to the first material or second material, a bridge rectifier connected to the at least one electrode to transform the power generated into direct current from alternating current, a storage unit for storing the power generated by the power generator, a sensor that gathers information concerning a downhole environment, and a microcontroller and transceiver unit to manage the power generated by the power generator and transmit information gathered by the sensor.