SUSTAINABILITY:

When discussing the importance of sustainability, they are often tied to the four laws of ecology. The first law, everything connects to everything else, reflects how the process of engineering is interconnected to everything. For example, the design and manufacturing processes create jobs on the job market promoting a good economy. The second law, everything must go somewhere, describes how all materials are recycled through the environment. Old electronics and ICs are often made into landfills when they cannot be recycled. The third law, nature knows best and bats last, expresses how nature is always adapting to the surrounding environment. The fourth law, there's no such thing as a free lunch, reflects how every process requires energy. The manufacturing plant requires energy to run, and the products designed need energy to work. Therefore, in order to preserve our planet, the issues of sustainability need to be considered to promote better engineering.

Performance often sacrifices power consumption. While CMOS logic consumes power, it only consumes dynamic power during the voltage swing from high to low or from low to high. The longer the gate stays in the transient state between high and low, the less power it consumes per transition. Parasitic capacitances of each MOSFET and the wire cause delay. The goal of creating low-power gates is to lower the parasitic capacitance of the device, by shrinking the device. Shrinking the device will only limit power consumption to a certain extent, as parasitic capacitances are always present, no matter how small. Also, integrating ECL circuits into ICs leads to very fast switching speeds, but it consumes a lot of power since it is drawing a continuous current. Therefore, ECL ICs are not useful for low performance circuits. Power dissipation can further be improved in digital design by using an asynchronous design. The clock wastes power because it continues running even when it's not need. By switching to an asynchronous design, power can be saved, and the speed can also increase. Sun is currently researching asynchronous design because clock frequency is starting to become a bottleneck to performance and power 7.

Besides decreasing chip power consumption, one has to remember that the chip fabrication process is also energy intensive. A more efficient manufacturing process can save chip manufacturers millions. The plants used to manufacture these widely used transistors can greatly conserve energy by taking measures to take a green approach, and as a result save money in operations cost and help out the environment at the same time. Using LEDs or florescent lighting, shutting down energy consumption in parts of the plant that are unused, or recycling silicon are all ways to do it, which leads to good economics. If all plants can give an equal effort toward these goals, our world would be a cleaner, better, greener, and more sustainable place. Intel's new plant for 45nm is projected to save $1 million in the next five years because of LEED certification 1. Also, manufacturers are re-designing products with reduced parts and materials in order to make them more environmentally friendly. Old electronic waste are usually thrown away and recycled into landfill, even though some may be still functional. Therefore, a more recyclable product is desired 6.

With better design and selection of which MOSFET circuits to implement, engineers can also help to conserve more energy. The ability for us to manufacture silicon wafers with the NMOS and PMOS arranged in a CMOS pattern today, as oppose to before, is an example of how the growth of technology results in higher efficiency. Without needing the larger parts that the Resistive load inverter requires is another benefit since we use less resources. When we manage to find ways to reduce the use of raw materials, it means a better overall picture for all. For example, the exportation of coltan in the Democratic Republic of Congo, has caused many issues. Coltan is an ore used to produce tantalum, which is used to produce capacitors for many electronics used today. 2 However, since the Congo is politically unstable, many neighboring militias raid and illegally smuggle this precious ore in order to fund themselves, which will never end the conflict throughout Africa. 5.4 million people have died from war-related causes in the Republic of Congo since 1998 3.

The system design, when designing any system, looks at different viewpoints, not just the technical viewpoint of an electrical system. An electrical system is designed in a certain social, economical, and political context. In electronics, there is the digital divide, where increasing gap between the technologies of the first world and the developing world 4. Programs, such as One-Laptop-Per-Child, whose goal is to provide affordable laptops to children in the developing world, tries to address the divide 5. A design must also useful in order for it to stand the test of time and not turn into waste. We must consider the full lifecycle of a design, including disposal. When the disposal of the object is taking into consideration during design, the object will less likely become useless unconvertible waste at the end of its life cycle.

1 Sharon Gaudin, "Intel's New 45nm Penryn Plant Goes Green" Computerworld, Tuesday, October 30, 2007.

2 Wikipedia, The Free Encyclopedia ‚Coltan. Available http://en.wikipedia.org/wiki/Coltan

3 IRC, International Rescue Committee, Special Report: Congo. Available http://www.theirc.org/special-report/congo-forgotten-crisis.html?gclid=CIb5tuOlu5MCFSUaagodshf6Cg

4 Kate Williams, "What is the digital divide?" University of Michigan, 2001. http://www-personal.umich.edu/~katewill/kwd3workshop.pdf

5 Unknown, The OLPC Wiki. http://wiki.laptop.org/go/The_OLPC_Wiki

6 Jamais Cascio,"Sustainability Electronics" Available http://www.worldchanging.com/archives/002088.html

7 "Beating the Clock." Sun Research Available http://research.sun.com/features/async/

Braun's comments

What does "circuit extent" mean in the first paragraph?

Analyze all four "E"s of sustainability linked via the laws of ecology to explain how experiments and ICs contribute to or prevent sustainability.