These household products designed by Bauhaus University graduate Weng Xinyu mimic human emotions and misbehave when left alone (+ slideshow).

A clock that tries to cut off its face when not watched and a lamp that switches itself off when left unattended are among the items in the range.

Weng Xinyu, who designed the products as part of his final year project, named the collection Good Medicine Tastes Bitter after a Chinese proverb.

"Good Medicine Tastes Bitter. Although its taste is not so pleasant, at least it cures the disease," he explained.

“In this project I tried to create a series of products that are not so useful, but have good intentioned messages inside,” he said.

Applying this remedial concept to the collection, Weng has attributed each object with characteristics that dictate how they can be used.

The designer set out to question whether products always need to be useful, or if they could be used as a vehicle for an idea, by asking: "Do products always have to satisfy the users?"

Angry Lamp is a light that irritatingly or conveniently switches itself off if left burning for too long.

It also shuts off if it finds itself in competition with another light source.

This behaviour is designed to remind users to switch off the appliance when not in use.

A clock that self-mutilates when not watched – Time Killer – attempts to disconnect its face from its body by slowly sawing through the timber that connects it with the wall, stopping only when approached.

The Tangible Memory photo frame mists over with time to obscure the image it contains, which can only be revealed again when rubbed.

A light that doubles as a shadow puppet theatre, titled Shadow Play, completes the homeware range.