Sign up for
Participate with your entry in one of our professional or student awards.Sign up for an award
You are using an outdated browser. Please upgrade your browser to improve your experience.
The manhole covers will be flooded by the rain on rainy days. Many accidents might happen for the lost covers that are leaded by which the inner high air pressure.Using PZT deformation of the covers generats electricity for the orange warning lamp after missingthe covers. The orange may through something, so it can protect the safty of the people
Xujiang Zhao Yao He Yueya Qu Jingwen Wang