"On-board microbattery power is fast becoming essential in many of today’s emerging technologies. Down-scaling in the micro-electronic industry has far outpaced advances in small-scale electrical power supplies. The absence of on-board power is a hinder to advances in many critical areas: micro-electronic devices and biomedical micro-machines. However, nano-materials and -structures provide new resources to attack the problem. MEMS devices will change our lives completely - given micropower sources. These include microsensor arrays, micro-vehicles, identification cards, memory backup, and biomedical micro-machines (pacemakers, defibrillators, neural stimulators, drug delivery systems). Insufficient power from 2D-MB configurations inspires this search for a 3D-MB using cheap and light micro-/nano-fabrication materials. We also probe whether related techniques can improve the performance of conventional Li-ion batteries. Can multicomponent assembly be replaced by a single interpenetrating nano-architectured anode/cathode element separated by an electrolyte? This would greatly cheapen conventional rechargeable Li-ion batteries for typically EV/HEV applications. Our major objectives are: • Synthesis and fabrication of novel nano-architectured battery materials and MB components. • Implementation in fully integrated thin-film 3D-MBs with current and power densities per unit footprint area of 70-100 μAh and 150-200 μW for 50-100 reversible cycles. • Implementation of at least some of these 3D-MB concepts in conventional normal-scale Li-ion battery fabrication. • ""Proof-of-concept"" by showing that some 3D-MB device from the project can power both a MEMS and a medical device. The project thus establishes 3D nano-architectures, micro-/nano-fabrication approaches, and the enabling Science for a whole new generation of microbatteries."