Semiconductor devices and methods of manufacture thereof are disclosed. Each of the shopping carts includes a weight detector to measure the weight of items placed therein and a transmitter to transmit the measured weights over a wireless communications link. This can reduce the risk of contamination of the transported materials and can also reduce the use of chemicals such as adhesives and bonding agents. An energy storage circuit is associated with each rectifier unit and is connected in parallel to a first busbar system. The fibers are substantially uniformly distributed over the internal surface providing a surface coverage of 2 to 20 percent. The supporting member can easily squeeze out the air between the sticker and the base.