Shelly Minteer and her colleagues from St. Louis University has been working on prototypes of a sugar fueled fuel cell to power portable electronics. The fuel cell works by using an enzyme to break down the sugar and gain electricity for the system. She has used sugar water, flat soda, tree sap and drink mixes successfully in the fuel cell. Shelley is currently powering a hand held calculator with this device. She hopes that in the future she will be able to use this renewable and biodegradable source of power as a battery replacement. The US Department of Defense, who funded the work, hopes that she will be able to generate enough electricity to power their portable battlefield gauges and sensors.