SpreadTHAT!
SpreadTHAT is a butter knife that has an ability to cut cold butter and spread butter with no effort. It turns cold butter into a amazing creamy goodness on your pancakes or toast! Heat is the main is a key role of SpreadTHAT, it uses your body heat and it transfers straight towards your knife, and melts butter before your very eyes.
This is related to engineering: The have to design the butter knife to be able to draw heat from you hand to transfer it to the butter knife. It takes a lot of trail and error to get the design right, and you have to focus and work with a team to design/complete the product.
Related Stories:
https://www.gadgetreview.com/spreadthat-butter-knife https://www.theguardian.com/technology/2015/sep/09/kitchen-gadgets-review-self-heating-butter-knife