Hair-like surfaces in nature consist of high-aspect-ratio fibers with diameters below 100μm, falling to several tens of micrometers in softer hairs. These fine fiber arrays govern tactile softness, flexibility, surface texture, and mechanical response. Conventional fiber-spinning methods produce fine fibers effectively but offer limited control over the position, direction, and patterned arrangement of individual fibers. Here we propose a fused deposition modeling (FDM)-based strategy that combines melt extrusion with geometric drawing to fabricate PLA hair-like fibers. PLA melted fully at the processing temperature of 250oC, well below the thermal degradation onset near 330oC. DSC analysis showed that faster cooling suppressed thermodynamic crystallization, indicating that the final fiber structure is governed by drawing history and rapid cooling rather than by increased crystallinity. As the printing speed increased, the fiber diameter decreased nonlinearly, following D ≈ 106.3 v^-0.45, in excellent agreement with the D  v^-0.5 scaling predicted by the continuity equation. Tensile strength and modulus increased with printing speed, whereas elongation and toughness decreased, indicating drawing-induced molecular orientation. These results demonstrate that FDM can serve as a programmable platform for fabricating biomimetic hair-like fiber arrays with predictable diameter and mechanical properties.

Dew generation on an outer surface is considered as an important issue to be settled in the field of home appliances. In the case of a refrigerator that is subject to the dew generation problem on the surface of an outer-door of refrigeration thread, and so as to solve this problem, the electric heater is generally used for drying the dew. However, the heater inevitably requires electrical power consumption that is one of critical issues on the refrigerator. In this study, to prevent dew generation without the heater, a method of using induced heat from room temperature was proposed. In edge sides of a door, high conductive plates are installed and received the heat from outside that is relatively high temperature, and the heat is transferred onto dew generation region. Using prototypes, performance test was conducted under a certain temperature and humidity condition. The experimental results show that the surface temperature on the dew generation region was increased about 0.3~ 2.5℃ without use of any heater.

A slide-rail system is widely used in home appliances, furniture, mechanical rigs, and so many other applications; due to its high strength and performance for easy moving heavy objectives. In general, a pair of side slide-rails is set on both sides of a drawer to support and move it. So an unbalanced sliding motion can occur during opening and closing a drawer with pull and push force. To settle this problem, single central slide-rail having three collapsible rail-bodies was firstly proposed in this work. ‘H’-beam shaped rail-body was newly designed to have enough bending and twisting strength. The experimental test showed that the proposed rail could be applied to large-size home appliances for easy moving drawer with heavy weight.