Abstract: Wireless sensor networks have become possible because of the on-going improvements in sensor technology and VLSI. One issue in smart sensor networks is achieving efficient operation because of the limited available power. For important classes of sensor networks, such as biomedical sensors, the locations of the sensing nodes are fixed and the placement can be pre-determined. In this paper, we consider the topology that best supports communication among these sensor nodes. We propose a power-aware routing protocol and simulate the performance, showing that our routing protocol adapts routes to the available power. This leads to a reduction in the total power used as well as more even power usage across nodes. We consider different routes and topologies, demonstrating the difference in performance and explaining the underlying causes.