Abstract: Provided herein are protective masks made with polymer-based materials and methods of forming the materials. Methods of forming the interlaced polymer-based materials comprise applying adhesive to a substrate, electrospinning a first polymer solution onto the substrate from a first group of spinning electrodes, electrospinning a second polymer solution onto the substrate from a second group of spinning electrodes, and applying hot air to dry the polymer-based materials electrospun from the first polymer solution and the second polymer solution to form the interlaced polymer-based materials.

Abstract: A stator assembly comprises a first core member and a plurality of second core members. The first core member comprises a first core member body, a plurality of cores and a plurality of receiving recesses. Each of the cores comprises a first yoke portion, a first tooth portion, a first coil and a first insulating bobbin. The second core member comprises a second yoke portion, a second tooth portion, a second coil and a second insulating bobbin. The first core member is engageable with the plurality of second core members in a manner such that the second yoke portions are fixedly received in the receiving recesses respectively with each of the second core members arranged interposed between each adjacent pair of cores so that the arc-shaped ends of the first tooth portions and the second tooth portions form an annular shape.

Abstract: A heater apparatus comprises a housing, and a plurality of heating elements provided in the housing. The housing includes a front side provided with a first heat outlet for spreading heat in a first direction, and a top provided with a second heat outlet for spreading heat in a second direction perpendicular to the first direction. Moreover, the second heat outlet is operable to switch between a closed state for blocking heat spread and an open state enabling heat spread in the second direction.