1. Doctoral Researcher, School of Mechanical Engineering, Univ. of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
2. Reader, School of Civil Engineering, Univ. of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
3. Senior Lecturer, School of Civil Engineering, Univ. of Birmingham, Edgbaston, Birmingham B15 2TT, U.K. (corresponding author).
4. Lecturer, School of Mechanical Engineering, Univ. of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
5. Professor of MEMS Technology, School of Engineering, Design and Manufacturing Systems, Birmingham City Univ., Millennium Point, Curzon St., Birmingham B4 7XG, U.K.; formerly, Senior Lecturer, School of Mechanical Engineering, Univ. of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.