**Hélder Puga**

CMEMS-UMinho, Center for Microelectromechanical Systems, Mechanical Department, University of Minho, 4710-057 Braga, Portugal; puga@dem.uminho.pt; Tel.: +351-252-510-220

Received: 6 April 2020; Accepted: 8 April 2020; Published: 9 April 2020
