Biomimicry
Spider web door
There are many different kinds of spider webs. All may be used to strengthen the door. The webs are: Orb, Tangle, Funnel, Tubular, and the Sheet web. All of these webs serve different purposes, but all provide strength for the spider.
Spiders have created strong webs that can be beneficial to humans.
This door will be a normal door, but it will be wrapped in the spider web. The spider web strengthens the structure of the door. On the outside of that will be a coating of plexiglass. This coating will strengthen the door even more.
Another use for the spider web is that it may be used on a car. This would protect cars from being badly damaged in a wreck.
One adaptation for this door is that the coating can be taken off. In doing this, the stickiness of the web will be exposed. This will catch any thieves or dangerous people before they break into a house.
Another adaptation is that this web may be used on a window. It will provide the same protection, but will just be on the outside of a window.
One more adaptation is that the spider web may simply be placed on the door, rather than wrapped around it. This will strengthen the door as a whole, rather than just protect it.
In the picture attached, The top image is an example of what the door would look like with a spider web placed on the door. The middle image is an example of what the door would look like with plexiglass. The bottom image shows the door with a spider web wrapped around it.