Energy: Although sustainability issues are often seen on a grand scale (i.e. saving or generating large amounts of power), those same principles apply to even a small circuit involving something as simple as a piezoelectric buzzer. Every bit of energy saved counts. The piezoelectric buzzer is often not used because of its issues with not having a flat response, even though it consumes little power as compared to speakers, and also takes minimal space. This application provides a solution for those engineers considering switching to a speaker simply because the piezoelectric buzzer has a very peaky response and resonant frequency varies from buzzer to buzzer. The design idea allows engineers to use the buzzer (often a lower power solution), by using a PIC to find the resonant frequency at which to operate the buzzer. In his design idea, Carlos Cossio also provides a method by which to harvest energy using a piezoelectric buzzer and store it in a super capacitor. As ICs become smaller and consume less power, methods like the latter can be used to provide significant amounts of energy to portions of the circuit. Ozbeks idea does require some minor extra power consumption because the buzzer has to be driven at multiple frequencies initially to find its resonance point.

 

Environment: Environmental issues continue to be top priority of many companies. Companies will find that the piezoelectric buzzer is small, simple, cheap, and easily recycled (the basic parts of the buzzer consist of a metal and ceramic plate). Another major environmental benefit is the size of the buzzer. The piezoelectric buzzer is significantly smaller than its counterpart speaker and can produce reasonably large sound output (dB). This design idea allows engineers to use piezoelectric buzzers confidently, knowing that the buzzer will produce a minimum level of sound and will operate at resonance. The design idea significantly impacts two major environmental issues as illustrated above, size and reuse.

 

Economics: The piezoelectric buzzer is one of the cheapest options available for generating simple audio tones (one frequency). Ozbeks method by which to operate at the resonance of each individual buzzer provides more incentive for engineers to use it by eliminating the major issue which most engineers find when working with piezoelectric buzzers (resonant frequency varies from buzzer to buzzer and the frequency response is very peaky).

 

Equity: Equity in this context can be analyzed through availability of the design idea and the piezoelectric buzzer. The design idea and the buzzers are available to everyone and more so because the piezoelectric buzzer is so cheap. The only additional part needed is a microcontroller which is also not very pricy (PIC). By limiting our negative impact on the lives of others through the environment and economy we are establishing equity.

 

 

1. Engineer processes and products holistically, use systems analysis, and integrate environmental impact assessment tools.

 

This design idea takes into consideration its environmental impact by minimizing power consumption to produce audio, and also minimizing space consumption and parts (PIC, small buzzer)

 

2. Conserve and improve natural ecosystems while protecting human health and well-being.

 

N/A

 

3. Use life-cycle thinking in all engineering activities.

 

The design idea takes the life of the product into consideration by making a constantly adjusting driver which always finds the resonant frequency of the buzzer even if it changes over time, temperature, or other variables.

 

4. Ensure that all material and energy inputs and outputs are as inherently safe and benign as possible.

 

Materials used for the piezoelectric buzzer are minimal, safe, and recyclable. (Ceramic and metal plates)

 

5. Minimize depletion of natural resources.

 

The size and minimal material use of the piezoelectric buzzer along with its capabilities minimizes its impact on natural resources while also increasing performance through the design idea.

 

6. Strive to prevent waste.

 

N/A

 

7. Develop and apply engineering solutions, while being cognizant of local geography, aspirations, and cultures.

 

N/A

 

 

 

 

8. Create engineering solutions beyond current or dominant technologies; improve, innovate, and invent (technologies) to achieve sustainability.

 

The nature of this design idea allows for small scale sustainability. As stated above, the buzzer can be used to harvest small amounts of energy; it also consumes very little energy and provides a clean and loud sound output at resonant frequency (the design idea helps locate this frequency).

 

9. Actively engage communities and stakeholders in development of engineering solutions.

 

To accomplish the above, engineers would have to run this idea by engineering management and considering its small scale, stakeholders would probably not be very interested. An idea of this sort would probably be discussed within an engineering team, and its results would be reported to upper level managers and marketing teams.

 

 

Reference:

 

[1]. CUI Inc. CEP-1114 piezo audio transducer (datasheet). January 31, 2007

[2]. Ozbek, Mehmet. "Piezoelectric driver finds buzzer's resonant frequency." Design Ideas. EDN. (August 7, 2008): pg. 76

[3]. Cossio, Carlos. “Harvest energy using a piezoelectric buzzer.” Design Ideas. EDN.

(March 20, 2008): pg 94

[4]. D. Braun and Cal Poly Electrical and Computer Engineering Students, “Cal Poly’s wiki for Sustainability in Integrated Circuits,” Available: http://sustainability-and-ICs.pbwiki.com/.

[5]. Developed by more than 65 engineers and scientists at the Green Engineering: Defining the Principles Conference, held in Sandestin, Florida in May of 2003. The preliminary principles forged at this multidisciplinary conference are intended for engineers to use as guidance in the design or redesign of products and processes within the constraints dictated by business, government, and society such as cost, safety, performance and environmental impact. From U.S. EPA, What is Green Engineering, Sept. 13, 2007, Available: www.epa.gov/oppt/greenengineering/pubs/whats_ge.html.

 

[6]. D. Braun. “Sustainability Analysis Assignment,”

Available: http://courseware.ee.calpoly.edu/~dbraun/courses/ee413/SustainabilityAnalysis.html