Adventures on the unbeaten path: Nano-scale circuits, Nano-materials, and Bio-Cellular Engineering

Tuesday, March 31, 2009
7:00 PM
Free and open to the public

I explore challenges facing CMOS technology, Nanotechnology, and Bio-Nanotechnology. Innovative ideas to the challenges facing these technologies, and leveraging the inherent strengths of these technologies to solve broader problems are of paramount importance. Firstly, we consider nanoscale CMOS technology which continues to provide performance improvements at both the device and circuit level for many of the important metrics of interest. However, thermal noise has not benefited much from scaling and has even increased in some cases due to parasitic noise sources. To this end, I have explored conventional low-noise amplifiers as a vehicle for understanding noise issues at GHz frequencies. In-depth exploration has led to the invention of an ultra-low noise amplifier that combines the strength of nanoscale technology to mitigate thermal noise arising from imperfect gate materials and non-quasi-static effects.

Secondly, I examine the space of nanomaterials particularly focusing on carbon nanotubes (CNTs) which are considered one of the premier exploratory nanomaterials. Carbon materials have been one of the major materials in the history of modern civilization over the past 120yrs, initially for applications in electric lighting, and then as composites in the aerospace industries and more recently for diverse electronic applications. Carbon nanotechnologies promise improved devices, and products that would enhance our quality of life. In the past decade, challenges regarding circuit performance, high-quality material synthesis and device physics have been pressing issues. I elucidate on recent progress in three key areas of fundamental significance including:

1. Comprehensive carbon nanotube analytical device physics and modeling with demonstrated validation by state of the art experimental nanotube devices. The validated analytical model was enabled by innovations arising from a sustained focus on the physics of CNTs resulting in the first set of equations for all the basic circuit parameters. CNTs operating as a quantum transistor show interesting circuit properties that represent a paradigm shift from conventional transistors.

2. Synthesis of perfectly aligned carbon nanotubes grown on crystalline substrates. Systematic surface science studies reveals the dynamics of the surface chemistry and physics leading to the first demonstration of high-density aligned growth on a full-wafer, a significant step forward for future CNT technologies for high-performance analog circuits.

3. In addition, we have developed a large-scale low-temperature hybrid nanotechnology as an enabling technology for highperformance nanomaterial electronics.

Lastly, we have recently been developing a bio-nanotechnology specifically for probing the properties of the cell that is the smallest living unit in all living beings. Our motivation is to enable real-time telemetry for understanding the basic science of cell biology that will inevitably lead to improved healthcare and quality of life. I will elucidate on our recent strategy, innovations, and challenges going forward.

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Deji Akinwande

Doctoral candidate
Stanford University