Performance evaluation of aluminum/phosphate cell for powering small electronic devices

• ZnO activation of metallic Al for generating electricity for bioelectronic applications.
• Two cells operating in physiological saline buffer produce an open-circuit voltage of 1.66 V.
• Sufficient power generated to power a light-emitting diode.

We report on an innovative membrane-free aluminum/phosphate cell based on the activation of aluminum (Al) as anodic material using ZnO nanocrystal in phosphate rich electrolyte that is capable of generating sufficient power to power a light-emitting diode (LED), selected as a model of a small electronic device. The energy from the cell is periodically supplied in high power bursts due to the charge and discharge cycle of the capacitor. The entire process is controlled by a switched capacitor regulator. The Al/phosphate cell was studied in neutral 100 mM phosphate buffer solution (7.4) at a temperature of 25 °C. We demonstrate that two Al/phosphate cells connected in series can generate an open circuit voltage (Voc) up to 1.66 V to continuously power a LED via a switched capacitor regulator circuit. The switched capacitor regulator circuit enabled the 1 μF capacitor to store the incoming power from the cell and discharge it in a large power burst to supply the necessary drive strength required by the LED. This new Al/phosphate cell configuration is a ‘green’ alternative to the use of glucose abiotic and biofuel cells for powering ultra-low power implantable electronic devices.