| 摘要 |
A shielding device, 10, comprises at least two of: a carbon nanotube (CNT) and graphene hybrid, 16, a ferrite material, 18, and a metal (figure 4, 24). The shield is intended to block radio frequencies. The shield may have outer layers made of plastic. The shield may be configured to block 13.56MHz or 125kHZ frequencies. The shield may be less than 2mm in thickness. The shield may comprise two separable shielding devices. The shield may be configured as a removable document sleeve for e-documents such as passports. A second embodiment is for a shielding device (figure 6A, 30) which has a planar body for receiving a card (figure 6B, 32) (e.g. credit card, debit card, smart card, RFID card, identity card, RFID tag), the card has a projecting portion (figure 6B, 38) (e.g. raised writing/characters), the shield has a raised surface portion (figure 6A, 34, 36) for abutting the card and preventing slippage. |
