Donald Edward Adams

Scanning probe charge reading of ferroelectric domains

A scanning probe charge-detection technique based on direct piezoelectric effect is demonstrated to read alternating bit polarizations in a ferroelectric media The bit signal is generated by spatially modulating charges interacting with a probe tip scanning in contact with the media. A periodicity of the bits is used with an appropriate scan speed to modulate the signal frequency. A signal-to-noise ratio of 10 dB has been achieved for a contact force of 100 nN. The modulation of the bit signal frequency into the 2 kHz data rate is achieved by coupling 0.4 μm spacing between alternating polarizations with scanning speed of 1.6 mm/s.

Nanochip: A MEMS-Based Ultra-High Data Density Memory Device

The paper provides an overview of a probe storage device development. The main results are related to successful development of ferroelectric memory, MEMS micro-mover with large range of motion and an array of cantilevers with sharp tips (read–write heads), demonstrating wear resistance of the tips, integration of memory material into the MEMS process, integration of MEMS cantilever process with CMOS, development of analog front end electronics, including read channel and servo system, and a controller for a storage device.