Advances in soft robotics, materials science, and stretchable electronics have enabled rapid progress in soft grippers. Here, a critical overview of soft robotic grippers is presented, covering different material sets, physical principles, and device architectures. Soft gripping can be categorized into three technologies, enabling grasping by: a) actuation, b) controlled stiffness, and c) controlled adhesion. A comprehensive review of each type is presented. Compared to rigid grippers, end-effectors fabricated from flexible and soft components can often grasp or manipulate a larger variety of objects. Such grippers are an example of morphological computation, where control complexity is greatly reduced by material softness and mechanical compliance. Advanced materials and soft components, in particular silicone elastomers, shape memory materials, and active polymers and gels, are increasingly investigated for the design of lighter, simpler, and more universal grippers, using the inherent functionality of the materials. Embedding stretchable distributed sensors in or on soft grippers greatly enhances the ways in which the grippers interact with objects. Challenges for soft grippers include miniaturization, robustness, speed, integration of sensing, and control. Improved materials, processing methods, and sensing play an important role in future research.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201707035

Soft Robotic Grippers.

Owing to advances in micro- and nanofabrication methods over the last two decades, the degree of sophistication with which solid surfaces can be engineered today has caused a resurgence of interest in the topic of engineering surfaces for phase change heat transfer. This review aims at bridging the gap between the material sciences and heat transfer communities. It makes the argument that optimum surfaces need to address the specificities of phase change heat transfer in the way that a key matches its lock. This calls for the design and fabrication of adaptive surfaces with multiscale textures and non-uniform wettability. Among numerous challenges to meet the rising global energy demand in a sustainable manner, improving phase change heat transfer has been at the forefront of engineering research for decades. The high heat transfer rates associated with phase change heat transfer are essential to energy and industry applications; but phase change is also inherently associated with poor thermodynamic efficiency at low heat flux, and violent instabilities at high heat flux. Engineers have tried since the 1930s to fabricate solid surfaces that improve phase change heat transfer. The development of micro and nanotechnologies has made feasible the high-resolution control of surface texture and chemistry over length scales ranging from molecular levels to centimeters. This paper reviews the fabrication techniques available for metallic and silicon-based surfaces, considering sintered and polymeric coatings. The influence of such surfaces in multiphase processes of high practical interest, e.g., boiling, condensation, freezing, and the associated physical phenomena are reviewed. The case is made that while engineers are in principle able to manufacture surfaces with optimum nucleation or thermofluid transport characteristics, more theoretical and experimental efforts are needed to guide the design and cost-effective fabrication of surfaces that not only satisfy the existing technological needs, but also catalyze new discoveries.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/8A3CC28A80AFA422AB5C8266816ECF6B/S2329222914000099a.pdf/div-class-title-surface-engineering-for-phase-change-heat-transfer-a-review-div.pdf

Surface engineering for phase change heat transfer: A review

Review of boiling heat transfer enhancement on micro/nanostructured surfaces

Boiling water in small channels that are formed along turbine blades has been examined since the 1970s as a means to dissipating large amounts of heat. Later, similar geometries could be found in cooling systems for computers, fusion reactors, rocket nozzles, avionics, hybrid vehicle power electronics, and space systems. This paper addresses (a) the implementation of two-phase microchannel heat sinks in these applications, (b) the fluid physics and limitations of boiling in small passages, and effective tools for predicting the thermal performance of heat sinks, and (c) means to enhance this performance. It is shown that despite many hundreds of publications attempting to predict the performance of two-phase microchannel heat sinks, there are only a handful of predictive tools that can tackle broad ranges of geometrical and operating parameters or different fluids. Development of these tools is complicated by a lack of reliable databases and the drastic differences in boiling behavior of different fluids in small passages. For example, flow boiling of certain fluids in very small diameter channels may be no different than in macrochannels. Conversely, other fluids may exhibit considerable “confinement” even in seemingly large diameter channels. It is shown that cutting-edge heat transfer enhancement techniques, such as the use of nanofluids and carbon nanotube coatings, with proven merits to single-phase macrosystems, may not offer similar advantages to microchannel heat sinks. Better performance may be achieved by careful optimization of the heat sink’s geometrical parameters and by adapting a new class of hybrid cooling schemes that combine the benefits of microchannel flow with those of jet impingement. [DOI: 10.1115/1.4005300]

Two-Phase Microchannel Heat Sinks: Theory, Applications, and Limitations

Preface 1 - Twenty Years of Promises: Fullerene in Medicinal Chemistry Tatiana Da Ros 2 - Biomedical Applications of Functionalised Carbon Nanotubes Alberto Bianco, Raquel Sainz, Shouping Li, Helene Dumortier, Lara Lacerda, Kostas Kostarelos, Silvia Giordani, and Maurizio Prato 3 - Antioxidant Properties of Water-Soluble Fullerene Derivatives Florian Beuerle, Russell Lebovitz, and Andreas Hirsch 4 - Fullerenes as Photosensitizers in Photodynamic Therapy Pawel Mroz, George P. Tegos, Hariprasad Gali, Timothy Wharton, Tadeusz Sarna, and Michael R. Hamblin 5 - Photodynamic Inactivation of Enveloped Viruses by Fullerene: Study of Efficacy and Safety Vladimir V. Zarubaev, Oleg Kiselev, Inna Belousova, Vladimir Rylkov, Alexander Slita, Alexey Sirotkin, Pavel Anfimov, Tatyana Muraviova, and Andrey Starodubtsev 6 - Effects of Photoexcited Fullerene C60-Composites in Normal and Transformed Cells S.V. Prylutska, I.I. Grynyuk, O.P. Matyshevska, A.A. Golub, A.P. Burlaka, Yu.I. Prylutskyy, U. Ritter, and P. Scharff 7 - Biological Effects in Cell Cultures of Fullerene C60: Dependence on Aggregation State Levon B. Piotrovsky, Mikhail Yu. Eropkin, Elena M. Eropkina, Marina A. Dumpis, and Oleg I. Kiselev 8 - Gadolinium Endohedral Metallofullerene-Based MRI Contrast Agents Robert D. Bolskar 9 - Biomolecules Functionalized Carbon Nanotubes and Their Applications Daxiang Cui 10 - Applications of Carbon-Based Nanomaterials for Drug Delivery in Oncology Nicole H. Levi-Polyachenko, David L. Carroll, and John H. Stewart,IV 11 - Visualization of Carbon Nanoparticles Within Cells and Implications for Toxicity Alexandra Porter 12 - Pharmacological Applications of Biocompatible Carbon Nanotubes and Their Emerging Toxicology Issues Tae-Joon Park, Jeffrey G. Martin, and Robert J. Linhardt 13 - Solubility of Fullerenes in Fatty Acids Esters: A New Way to Deliver In Vivo Fullerenes. Theoretical Calculations and Experimental Results Franco Cataldo 14 - New Approach to QSPR Modeling of Fullerene C60 Solubility in Organic Solvents: An Application of SMILES-Based Optimal Descriptors A.A. Toropov, B.F. Rasulev, D. Leszczynska, and J. Leszczynski 15 - Functionalized Nanomaterials to Sense Toxins/Pollutant Gases Using Perturbed Microwave Resonant Cavities Aman Anand, J.A. Roberts, and J.N. Dahiya 16 - Cellular Nanotubes: Membrane Channels for Intercellular Communication Raquel Negrao Carvalho and Hans-Hermann Gerdes

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Medicinal Chemistry and Pharmacological Potential of Fullerenes and Carbon Nanotubes

Hybrid micro-nano structured thermal interfaces for pool boiling heat transfer enhancement

Carbon nanotubes (CNTs) have been reported to have very high thermal conductivity, ranging from 700 W/m-K to 3000 W/m-K. However, there are not many heat transfer applications where these CNTs are used. The two main reasons behind this are that, it is hard to grow the CNTs up to a macroscopic height and it is difficult to achieve good thermal contact between the CNTs and the surface of the heat source. We have overcome both these problems and obtained CNT bundles as tall as 2.5 mm and with different cross sectional areas that can be arranged in an array on a metallic substrate. Thus, these CNT bundles can act as fins having very high thermal conductivity to remove much higher heat flux compared to fins of similar dimension and configuration made of the customary materials such as copper or aluminum. Our calculation shows that in forced air convection cooling, a performance enhancement of 2 to 3 times can be achieved using just 2 mm tall CNT bundle fins, compared to a commercially available aluminum or copper heat sink that can remove a heat flux of 20-30 W/cm2. That way we can achieve a better heat removal performance as well as a reduction in the size of the heatsink, without deviating much from the most convenient and widely used cooling technique

P. M. Ajayan

Papers

Hybrid micro-nano structured thermal interfaces for pool boiling heat transfer enhancement

Carbon Nanotube (CNT) Fins for Forced Convection Cooling of High Power Microprocessors