1. Università Degli Studi di Cagliari, Dipartimento di Fisica, S. P. 8 Km 0.700, 09042 Monserrato (CA), Italy
2. National Physical Laboratory, Hampton Road, Teddington TW11 0LW, U.K.
3. Kuraray Company Limited, 2045-1, Sakazu, Kurashiki, Okayama 710-0801, Japan
4. Centre for Additive Manufacturing, The University of Nottingham, Jubilee Campus, Nottingham NG8 1BB, U.K.
5. School of Pharmacy, The University of Nottingham, University Park, Nottingham NG7 2RD, U.K.
6. IONTOF GmbH, Heisenbergstr. 15, 48149 Münster, Germany