Before revision: Energy neutral design is also a concept from Wireless Sensor Networks or Internet of Things -- where objects absorb energy from their immediate environment such as heat, motion or electromagnetic energy, in order to signal events wirelessly.
After revision: don't require plugging in -- theyEnergy neutral design is also a concept from Wireless Sensor Networks or Internet of Things -- where objects absorb energy from their immediate environment such as heat, motion or electromagnetic energy, in order to signal events wirelessly.