Thermally “<italic>Smart</italic>” Characteristics of Nanofluids in Parallel Microchannel Systems to Mitigate Hot Spots in MEMS

Abstract

Mitigation of 'hot spots' in MEMS employing in-situ microchannel systems requires a comprehensive picture of the maldistribution of the working fluid and uniformity of cooling within the same. In this article, detailed simulations employing parallel micro channel systems with specialized manifold-channel configurations i.e. U, I and Z have been performed. Eulerian- GHz quad core processor) under various processor load conditions has been studied and evidence of enhanced cooling of hot spots has been obtained from DPM analysis. The article sheds insight on to the behavior of non-homogeneous dispersions in complex flow domains and the caliber of nanofluids in cooling MEMS more uniformly and 'smarter' than base fluids.

Heat spreader with parallel microchannel configurations employing nanofluids for near–active cooling of MEMS

“…Employing nanofluids as coolants is a good option to achieve uniform cooling of microelectronic devices and modules thereby making the analysis of the performance of variant nanofluids as coolants important. Since nanofluids are reported to act as smart fluids in micro flow paths [21,22], it is essential to know the hydro dynamic behaviour of the same for design of the pumping system. Comparison of hydrodynamic characteristics of different types of nanofluids in PMCS has been illustrated in fig.…”

“…In reality, single phase fluids such as water are not expected to fulfil the cooling requirements. Employing nanofluids as working fluid is one of the best alternative solutions to attain enhanced cooling as these fluids demonstrate smart features [21,22] due to particle migration which enhances heat transfer characteristics.…”

“…To quantify the two important aspects discussed in preceding sections, i.e. 1) selection of the best configuration for uniform cooling of a given geometrical condition and for an applied heat load and 2) increasing heat transfer performance in a given configuration employing nanofluid compared with base fluid, a parameter termed as Figure of Merit (FoM) has been proposed [22]. FoM is defined in a way that it simultaneously considers enhancing the uniformity of cooling as well as reducing the maximum temperature within the PMCS.…”

“…FMF of U configuration is highest followed by I and Z configurations. Such observations are due to the highly non uniform distribution of working fluid (which is termed as maldistribution[21,22]) among the channels which are essentially due to the apparent positioning of channels with respect to manifold. However, as the pressure drop values observed in experiments agree within a margin of ±10%, the ratio of the maximum and minimum pressure drops leads to deviated values of the FMF.…”

Selecting Optimal Parallel Microchannel Configuration(s) for Active Hot Spot Mitigation of Multicore Microprocessors in Real Time

“…Among the several proposed methods, employing efficient heat transfer fluids such as nanofluids is one of the best methods, as reported by Li and Kleinstreuer [14], Escher et al [15] and Lee and Mudawar [16]. Employing nanofluids as working fluid in such complex flow domains not only improves cooling but also uniformity of cooling (Maganti et al [17]) because of smart nature of nanofluids at high temperatures, reported by Das et al [18]. In addition, there is the challenge of designing such effective cooling systems as in reality heat emitted by microelectronic devices will never be uniform and leads to further non-uniform cooling of microelectronic devices (Maganti et al [17] and Cho et al [19]).…”