Flat flexible polymer heat pipes

• Published in: Journal of micromechanics and microengineering 2013-01, Vol.23 (1), p.15001-6
• Main Authors: Oshman, Christopher, Li, Qian, Liew, Li-Anne, Yang, Ronggui, Bright, Victor M, Lee, Y C
• Format: Article
• Language: English
• Subjects: ALD; Application fields; Applied sciences; Copper; Exact sciences and technology; flat; Flats; heat pipe; Heat pipes; Heat transfer; Lightweight; polymer; Polymer industry, paints, wood; Technology of polymers; Thermal resistance; Thermoelectricity; Weight reduction
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/23/1/015001

Flat, flexible, lightweight, polymer heat pipes (FPHP) were fabricated. The overall geometry of the heat pipe was 130 mm × 70 mm × 1.31 mm. A commercially available low-cost film composed of laminated sheets of low-density polyethylene terephthalate, aluminum and polyethylene layers was used as the casing. A triple-layer sintered copper woven mesh served as a liquid wicking structure, and water was the working fluid. A coarse nylon woven mesh provided space for vapor transport and mechanical rigidity. Thermal power ranging from 5 to 30 W was supplied to the evaporator while the device was flexed at 0°, 45° and 90°. The thermal resistance of the FPHP ranged from 1.2 to 3.0 K W−1 depending on the operating conditions while the thermal resistance for a similar-sized solid copper reference was a constant at 4.6 K W−1. With 25 W power input, the thermal resistance of the liquid-vapor core of the FPHP was 23% of a copper reference sample with identical laminated polymer material. This work shows a promising combination of technologies that has the potential to usher in a new generation of highly flexible, lightweight, low-cost, high-performance thermal management solutions.