Michael DorseyTeam TRAPNovember 14, 2005
Introduction
Our project is the design of an autonomous robot built for the purpose of disposing trash. It will traverse a user-defined area using a wheelbase and front-mounted ultrasonic sensor to navigate, identify objects with a mounted color-identifying camera, and use a series of servo motors with an attached metal shovel to pick up and dispose of specific trash. The major components of the robot will include a printed circuit board, two ultrasonic sensors, motorized wheelbase with plastic casing, three servo motors, digital camera, LCD, keypad, metal shovel, two rechargeable batteries and a digital compass.
Many ethical and environmental issues come to focus during the design of the robot. On the ethical side, these matters deal with the final product that will be placed on the market. The consumer has the right to assume that the product they have purchased will work in its intended method, complete with safety documentation and mechanisms that will prevent any form of injury to both the consumer and any bystanders unless the product has been modified or misused. If this cannot be accomplished, then there runs a risk of liability that can hurt not only the consumers, but also damage the company both commercially and legally. This obligation raises moral issues that can sometimes compete with the technical ones needed to put an object out on the market.
On the environmental side, it is best summed by Malcolm McPherson when he said that “engineers have a greater potential impact on our environmental inheritance than members of any other profession and we,therefore, have a greater obligation and responsibility to see to its care. It is a daunting responsibility, replete with ethical andprofessional pitfalls. Engineering universities and colleges have a duty to make their graduates aware of these responsibilities” [1]. Our robot will be going through a complete lifecycle of manufacturing, normal use and finally disposal and recycling. All aspects of these phases are important; therefore it is our responsibility to care for the well-being of our fellow human beings so as to not damage the world around us with our product.
Ethical Impact Analysis
There are many problems that our team would face if we were to actually bring our product to the market. One of the issues would be the operating conditions that the robot would be working under. Since it currently has a generic and semi-open casing, there is no way that it would be able to work in the rain. The printed circuit board is under a layer of the plastic casing, but this would not be much of a deterrent. Plus, other components such as the camera and ultrasonic sensors would be completely exposed. There is also no lid on the trash can that will be attached to the rear, so if that filled up with water it would most certainly weigh down the robot. Another poor condition would be an area with poor lighting. Since the robot depends on the camera to identify trash based on color, without good lighting it might not be able to see the correct objects.
Another issue that deals with the physical structure of the robot are possible sharp edges and pinch points. We have a metal shovel/basket mounted on the front with many holes cut through to make it lighter. If not manufactured properly, they can have sharp edges that could physically injure a consumer. The same goes for the servo motors. They move in certain positions that could possibly catch a young child’s finger if there were no one paying attention. Also, with any other exposed circuit board, there is always the chance of electrical shock if someone is touching these boards during operation.
To address the issue of operating conditions, we would need to provide one of two things: a casing that would allow the robot to perform in these tough areas such as outside in the rain, on a rough terrain, in poorly lit areas and the like, or we would have to provide explicit documentation that would describe the exact working conditions the robot would need in order to perform correctly and maintain usability. To choose between the two would depend on the cost of casing and the marketing desires of the general consumer. If the casing is too expensive and the consumers do not use it outdoors very frequently, then functionality could be sacrificed.
The issue of the consumer being physically injured is a serious one. To combat this from happening, the idea of having proper casing comes to the forefront. With a well-designed case, it would be hard for the consumer to be casually injured while using the product. Also, to prevent any liability, we would place specific disclaimers in the documentation explaining that the casing is not to be removed. To further press this, warning labels would be placed in certain areas such as the numerous circuit boards, the servo motors, the metal shovel and the wheelbase. By using a plastic shovel instead of a metal one, you can avoid the issue of having sharp edges that could cut a consumer. This idea of a disclaimer can also be used in the issue of the microcontroller being internally altered to cause erratic behavior of the robot. Without these, it is possible for a consumer to report an issue to the government and bring up possible legal action [2].
The most dangerous and difficult issue to handle is the possibility of the robot going “out of control” since it does work autonomously. To prevent this from happening, the product will be tested thoroughly for every possible scenario and the user will not be allowed to reprogram the robot’s microcontroller.
Environmental Impact Analysis
There are three main stages that a product will go through in its life cycle, the first one being the manufacturing stage. Our robot will be made of six printed circuit boards, a metal shovel with metal servo motors, metal wheel motors with rubber wheels, a plastic wheelbase casing and two rechargeable batteries. Everything will be pre-made from other manufacturers except for our main circuit board and metal shovel. The metal shovel is strictly as it sounds, just sheet metal that is bent in a specific fashion to fit our robot’s needs. One detrimental product would be the main circuit board holding our microcontroller and other electronics. It contains products such as lead, glass-epoxy, ceramics, copper foil and many more. Some of the waste streams that are produced by circuit board production are: sanding materials, vinyl polymers, chlorinated hydrocarbons, copper, nickel, tin, and ammonia. Most are removed to landfills, into the air via combustion or through wastewater [4].
The stage of normal use does not pose any significant environmental impact. In fact, our product implies a positive impact on the environment since the overall objective of the robot is to pick up waste/recyclables. But looking at the devices on board, the only real threat would be the batteries, which are 7.2V nickel metalhydride rechargeable batteries. According to a Duracell data sheet, though, they provide no major negative impact while remaining intact. If they are damaged and leak battery fluid, are exposed to high temperatures or are physically abused, this condition can change [5].
At the end of the products life cycle, it is ultimately up to the consumer to decide where the disposed of product will end up. As stated above, there are hazardous materials that go into PCB assembly, including lead which can be very dangerous if placed in a water stream. Our product has six circuit boards which can be considered an extreme amount compared to other products. Combined with the rechargeable batteries and there are some serious issues that need to be dealt with in this phase of the lifecycle.
To combat the highly negative impact of manufacturing our circuit board, we can use different methods to produce the product. One such way is to use surface mount technology instead of dual-in-line package. This allows for “closer contact areas of chip leads, and therefore reduces the size of printed circuit boards required for a given number of packages…” Another method is injected molded substrate and additive plating. This method involves “heated liquid polymer…injected under high pressure into precision molds.” Cleaning can also be improved by substituting abrasive for aqueous cleaning and using non-chelated cleaning chemicals as opposed to chelated ones since it is not as hazardous [4].
As stated earlier, during the normal operation there is not as much of a threat. As long as the consumer uses common sense and refrains from tampering with the batteries and the circuit boards, there would not be any need for concern. The batteries are in a fine casing and would difficult for little children to break open.
At the end of the product’s life cycle, there are a few items that could certainly be recycled. Included in the documentation would be instructions for returning the product at the end of its lifecycle in its entirety. It could then be stripped down to its individual parts where they could be salvaged if still operable or properly disposed of if not. The shovel could be melted down and recycled to form a new one. The circuit boards can also be sent to companies who would remove the raw materials such as the silver, lead, gold and copper [6]. With the nickel metal hydride batteries, they can be “disassembled by shredding and/or hammer-mill. The electrolytes are neutralized; the heavy metals are recovered by pyrometallurgical processes; and the heavy metals are sold back into the manufacturing chain” [7].
There are many serious issues with a product that moves freely in the physical world. There are many opportunities for injury that have to be dealt with. But withproper and extensive testing prior to release, it is possible to avoid them. This comes down to an ethical decision by the manufacturer to ensure safety to the consumers. To help protect the environment, the manufacturer can only do so much. It is really up to the consumer to make the decision on where their product will end up. With consumer and producer working together, it is possible to make a difference in this growing electronic market.
List of References
[1] Splitt, Frank G. Engineering Education Reform: A Trilogy. Northwestern University. January 2003.
[2] U.S. Consumer Product Safety Commission. CPSC Home Page. Available:
[3] Meyer, D.G. Ethically and Environmentally Astute Product Engineering. Available:
[4] Environmental Protection Agency. Guides to Pollution Prevention: The Printed Circuit Board Manufacturing Industry. Available:
[5] Gillette Environment Health and Safety. Material Safety Data Sheet: Duracell Nickel Metal Hydride Batteries. Available:
[6] Joint Service Pollution Prevention Opportunity Handbook. Printed Circuit Board Recycling. Available:
[7] Battery Solutions, Inc. Nickel Cadmium / Nickel Metal Hydride. Available: