The background chapter documents your ongoing search for information to support your design. The chapter should review previous solutions to this or to similar problems. It should mention parts, designs, systems, approaches and devices that might solve your needs: You may discuss materials, environments or locations, safety & hazards, social and economic issues that affect your project, etc.
Contents of this chapter should go beyond just listing existing applications. The focus of this chapter should be on breadth of coverage: It should demonstrate that your group has investigated a wide range of information in the quest to make YOU the experts on all aspects of the design, and on technologies that could be associated with solutions.
Don't forget to investigate any ASME, ASTM, SAE, NIST, or other pertinent rules or specifications that might apply to your project elements. The frequent and effective use of images and figures is important. But don't let this chapter grow to unwieldy size: Be careful to maintain a lean, streamlined writing style and limit depth of coverage - focus instead on summarizing the highlights of your search for information.
Format of this chapter (and all chapters) should be per the format requirements linked on the course syllabus.