Low power high density random access memory flash cells and arrays using Fowler Nordheim tunneling for both programming and erasing. Transmission line consists of a termination member, outer and inner enclosure walls, high-density lining and throatmouth area. The wheel transducer according to the invention includes a tire made of ultrasonic wave permeable materials, probes combining ultrasonic emitterreceiver, a sliding plate and the means for reducing friction between the sliding plate and the bottom of the tire of the wheel transducer while flaw detection.