Ion-exchange membranes have been established for a variety of industrial applications, including energy and environmental technologies related to water treatment, fuel cells, and flow batteries. However, the limited tunability and adverse ion permeability-selectivity tradeoff exhibited by traditional ion-exchange membranes limit their development. To address this limitation, researchers at UC Berkeley developed a new class of composite ion-exchange membrane materials incorporated with highly tunable porous aromatic frameworks (PAFs). The Berkeley researchers show that an assortment of PAF variants can be easily embedded into charged membranes, where the choice of PAF filler can be used to optimize the physical, ion transport, and adsorptive properties of the membrane according to their targeted application. Material characterizations indicate that numerous charged membranes embedded with PAFs exhibit excellent dispersibility, interfacial compatibility, structural flexibility, and pH stability. Proton conductivity and water uptake measurements also indicate that the exceptionally high porosity of PAFs enhances ion diffusion in membranes, while abundant, favorable PAF-polymer interactions decrease non-selective swelling pathways typically observed in highly charged ion-exchange membranes. Furthermore, adsorption experiments demonstrate that ion-selective PAFs can be embedded into charged membranes to tune the ion selectivity of the membrane and also enable their use as membrane adsorbents. Test show promise for technology to improve the general performance and tunability of ion-exchange membrane technologies.

The selective separation of trace components of interest from various mixtures (e.g., micropollutants from groundwater, lithium or uranium from seawater, carbon dioxide from air) presents an especially pressing technological challenge. Established materials and separation processes seldom meet the performance standards needed to efficiently isolate these trace species for proper disposal or re-use. To address this issue, researchers at UC Berkeley developed a novel separation strategy in which highly selective and tunable adsorbents or adsorption sites are embedded into membranes. In this approach, the minor target species are selectively captured by the embedded adsorbents or adsorption sites while the species transport through the membrane. Simultaneously, the mixture can be purified through traditional membrane separation mechanisms. As a proof-of-concept, the researchers incorporated Hg2+-selective adsorbents into electrodialysis membranes that can simultaneously capture Hg2+ via an adsorption mechanism while desalinating water through an electrodialysis mechanism. Adsorption studies demonstrated that the embedded adsorbents maintain rapid, selective, regenerable, and high-capacity Hg2+ binding capabilities within the membrane matrix. Furthermore, when inserted into an electrodialysis setup, the composite membranes successfully capture all Hg2+ from various Hg2+-spiked water sources while permeating all other competing cations to simultaneously enable desalination. Finally, using an array of other ion-selective adsorbents, the Berkeley team showed that this strategy can in principle be applied generally to any target ion present in any water source. This multifunctional separation strategy can be applied to existing membrane processes to efficiently capture targeted species of interest, without the need for additional expensive equipment or processes such as fixed-bed adsorption columns.

Despite decades of effort, it remains challenging, if not impossible, to achieve similar transport performance similar to natural channels. Inspired by the known crystal structures of transmembrane channel proteins, protein sequence-structure-transport relationships have been applied to guide material design. However, producing both molecularly defined channel sizes and channel lumen surfaces that are chemically diverse and spatially heterogeneous have been out of reach. We show that a 4-monomer-based random heteropolymer (RHP) exhibits selective proton transport at a rate similar to those of natural proton channels. Statistical control over the monomer distribution in the RHP leads to well-modulated segmental heterogeneity in hydrophobicity, which facilitates the single RHP chains to insert into lipid bilayers. This in turn produces rapid and selective proton transport, despite the sequence variability among RHP chains. We have demonstrated the importance of:the adaptability enabled by the statistical similaritythe modularity afforded by monomer chemical diversity to achieve uniform behavior in heterogeneous systems. 

A new covalent organic framework (COF) with defective square lattice topology and exceptional water sorption properties stemming fro its unique framework structure. The COF exhibits a working capacity of 0.23 g(H2O)/g(COF) between 20 and 40% relative humidity without displaying hysteretic behavior. Furthermore, it maintains these promising water sorption properties after several uptake and release cycles. This material could be used as a sorbent for water harvesting or other water sorption related applications.

This technology combines air layer frictional drag reduction (ALDR) with super hydrophobic surfaces (SHS) to achieve frictional drag reduction of ALDR with significantly reduced gas flux. Thus, enabling increased net energy savings. The stable air layer is achieved with lesser gas flux when utilizing a SHS.Periodic air layers may replenish SHS, enabling drag reduction with reduced energy cost. Combinations of SHS and regular or other non-SHS surface may be used to control spreading of gas, thus facilitating formation of ALDR using discrete gas injection points better than previously achievable. Such surface variations could also be used to preferentially guide gas towards or away from propulsion, depending on desired outcome. By controlling ALDR regionally or globally on a surface, with or without SHS, this technology modifies flow around a hull. This mediates forces on partially or fully submerged objects, enabling control of flow patterns, resistance, steering, and/or dynamics.

Silicon photovoltaic (“Si-PV”) modules currently dominate the solar energy market. Increased progress into Si-PV efficiency enhancements combined with historically low module costs aim to decrease the overall Levelized Cost of Electricity (“LCOE”) to a point competitive with non-renewable energy sources. Despite recent LCOE reductions, Si-PV technology remains economically inferior to fossil fuels. Additionally, flat-plate Si solar modules generally require geographical locations with high direct normal incidence (“DNI”) sunlight conditions in order to maintain module performance. Both the strict DNI requirement and the high LCOE of Si-PV cells ultimately limit the dissemination of solar power into the global energy market. A solution for the capturing of diffuse sunlight includes the use of optical concentrators.  One class of optical concentrators includes luminescent solar concentrators (“LSCs”).  Luminescent solar concentrators have garnered interest due to their ability to utilize diffuse light and their potential for use in architectural applications such as large area power-generating windows. However, LSCs have not yet reached commercialization for photovoltaic power generation, largely due to their comparatively low power conversion efficiencies (“PCEs”) and lack of scalability.     Researchers at UC Berkeley and other educational institutions have developed luminescent solar concentrators that  can be designed to minimize photon thermalization losses and incomplete light trapping using various novel components and techniques.

Natural gas, composed primarily of methane, has many potential uses as a cleaner and more renewable source of energy than other fossil fuels. However, about 20% of US natural gas reserves contain levels of N2 that are too high for pipeline processing. Using natural gas from renewable sources also encounters this problem. Furthermore, in processing steps to create high-purity methane from its various sources, the removal of N2 remains a significant energetic cost. This separation is typically performed through cryogenic distillation, and improvements in energy efficiency of this separation are necessary to utilize the many available sources of methane. Switching to membrane or adsorbent-based technologies could potentially alleviate this challenge. Size selective molecular sieves and membranes have demonstrated some ability for separating N2 from CH4, but face problems with scalability and selectivity; and current adsorbents need significant improvements in selectivity and capacity for N2 to be commercially viable.  To address this situation, researchers at UC Berkeley have developed a new adsorbent V2Cl2(btdd) with exceptional affinity for nitrogen, such that early experiments already demonstrate a N2/CH4 selectivity of over 10x greater than any reported material. The Berkeley material is a permanently porous vanadium(II)-containing metal-organic framework (MOF). It represents the first example of a MOF with five-coordinate vanadium(II) centers as the primary metal node. The electronic properties of these five-coordinate V(II) centers make this MOF uniquely reactive towards relatively inert and weak electron acceptors, such as nitrogen, creating a stronger M–N2 interaction than any known MOF. Additionally, the high-density of V(II) centers translates to a high gas uptake capacity, qualifying this material as a promising N2/CH4 selective adsorbant. Key performance parameters can be tuned as the building blocks are synthetically modifiable.

There are an estimated 130 million wooden poles that support overhead power lines in the US.  Extreme weather, aging, storms or sabotage can all lead to potential damage of these poles and power lines, which can leave large areas without basic necessities.  Due to this risk, it’s anticipated that power utility companies will deploy sensors and corresponding energy harvesters to better respond to potential damage of this critical electricity grid infrastructure. To address this anticipated mass deployment of sensors and harvesters, researchers at UC Berkeley have developed technology improvements to harvesting of electrical energy from energized conductors carrying alternating currents, such as those on overhead and underground power lines (as well as power-supplying conductors in offices and dwellings).  These enhanced harvesters would improve the economics of deploying sensors across a national power grid.  The Berkeley harvesters can readily provide enough power to supply wireless communication devices, energy storage batteries and capacitors, as well as sensors such as accelerometers, particulate matter measuring devices, and atmospheric sensors.

Surface defects dominate the behavior of minority carriers in semiconductors and optoelectronic devices. Photoluminescence quantum yield (QY), which dictates efficiency of optoelectrics such as LEDs, lasers, and solar cells, is extremely low in materials with a large number of surface defects. Researchers at UC Berkeley and Lawrence Berkeley National Laboratory have developed a bis(trifluoromethane) sulfonamide (TFSI) solution for passivation/repair of surface defects in 2D transition metal dichalcogenide (TMDC). This air-stable solution-based chemical treatment provides unmatched photoluminescence QY enhancement to values near 100% without changing the surface morphology. The treatment eliminates defect-mediated non-radiative recombination, which eliminates the low performance limit of TMDC and enhances its minority carrier lifetime. This novel development can address surface passivation in numerous semiconductors which will lead to highly efficient light emitting diodes, lasers and solar cells based on 2D materials.

Over the last several decades, polymer membranes have shown promise for purifying various industrial gas mixtures. However, there are a number of potential applications in which highly polarizable gases (e.g., CO2, C3H6, C3H8, butenes, etc.) diminish membrane selectivities through the mechanism of plasticization. Plasticization is the swelling of polymer films in the presence of certain penetrants that results in increased permeation rates of all gases, but an unwanted, and often times, unpredictable loss in membrane efficiency. Current strategies for reducing plasticization effects often result in a reduction in membrane permeability. To address the need for plasticization-resistant membranes that retain good separation performance, researchers at UC Berkeley have developed a novel method for improving polymer membrane stability and performance upon the incorporation of metal-organic frameworks (MOFs). This method can be applied to a broad range of commercially available polymers as well as enable new polymers to be commercialized.

As the most reducing and lightest metal, lithium is a desirable battery anode material due to its abilities to yield a high cell voltage and a high specific energy capacity. Lithium ion (Li-ion) battery technology is expected to grow to a $30B industry in the next 5 to 10 years. This growth is largely driven by the introduction of electric vehicles which reached one million plug-in electric vehicles globally in 2015. Problems with Li electrodes have been investigated and challenges remain, including dendrite growth, flammability of organic solvents, and decomposition of the anions at the electrode. To address these challenges, researchers at UC Berkeley are developing single-ion, solid polymer electrolytes as replacements for liquid electrolytes. The investigators have demonstrated a solid-state battery system which uses single-ion conduction and leverages three-dimensional connectivity of polymer networks to provide superior mechanical strength and flexibility which affects bulk conductivity.

Nearly all hydrocarbons are generated from petroleum or natural gas processing. Hydrocarbon mixtures are separated into component fractions at scale for the commercial production of fuels and chemical feedstocks. These large-scale systems use a lot of energy and require many sub-systems with expensive adsorbents or membrane materials like zeolites, polymers, metal oxides, and carbon. Since many of these hydrocarbon mixtures have molecules with similar structures, properties, and reactivities, many of the technical challenges and associated high costs remain. Metal-organic frameworks (MOFs) hold promise for efficient and complex separations based on their desirable surface areas, tunable pore geometries, and adjustable surface functionality. To help align MOFs with challenges in hydrocarbon separations, researchers at UC Berkeley have developed thermally robust and tunable MOF materials which are capable of separating mixtures of saturated, unsaturated, and aromatic hydrocarbons. The researchers have demonstrated the purification of a four component gas-phase mixture. 

Conventional power conversion cycles which turn fuel into heat and heat into power are constrained by basic thermodynamic considerations. The most modern technologies have been limited to 60% even with multiple cycles combined (i.e. Brayton and Rankine combined cycle). Recent demonstrations have shown relative efficiency gains of 30% in both spark-ignited and compression-ignited regimes. Researchers at the University of California, Berkeley, are working to outdo these efforts by working on an ultra-high efficiency power cycle framework using argon as the working fluid. Early laboratory results suggest the argon engine could easily achieve 70% or greater thermal efficiency. Under such research the argon replaces nitrogen as the working fluid and is recycled in the closed-loop system.

There are many applications that require the storage of a high density of gas molecules. The driving range of vehicles powered by natural gas or hydrogen, for instance, is determined by the maximum density of gas that can be stored inside a fuel tank and delivered to the engine or fuel cell. In certain situations, it is desirable to lower the pressure or raise the temperature needed to store a given amount of gas through the use of an adsorbent. Developments in next-generation adsorbents, such as metal-organic frameworks and activated carbons, have shown certain weaknesses in terms of the amount of gas that can be delivered when an application has a minimum desorption pressure greater than zero and when a significant amount of heat is released during adsorption or cooling occurs during desorption. To help solve these problems, researchers at the University of California, Berkeley, have developed a next generation of materials using novel porous metal-organic frameworks that demonstrate unprecedented deliverable gas capacities. These engineered adsorbents maximize the amount of gas delivered during each adsorption/desorption cycle. This shows promise in developing next generation gas storage materials for applications with a wide range of operating conditions.

In recent years there has been a greater interest in making more energy efficient automobiles.  A number of plug-in vehicles (PEVs) or hybrid electric vehicles (HEVs) are offered by nearly every automaker today.  Although these vehicles offer a cleaner and more energy efficient alternative to traditional petroleum-fueled vehicles, mainstream consumer acceptance of these technologies is stymied by considerations of their premium price, limited travel range, and extended charging times, all consequences of current battery technologies. To address these problems, UC Berkeley researchers have developed an electro-mechanical flywheel system to be incorporated into PEVs and HEVs which increases efficiency, extends battery life and extends travel range making this battery/flywheel system more cost effective and more appealing to the mainstream consumer.  The system combines the chemical energy storage in a battery with the electro-mechanical energy storage in a flywheel to provide the system with both high power capability and high energy density.   

Supercapacitors are attractive energy storage devices due to their high-power capabilities and robust cycle lifetimes.   “Super” capacitors are named in part because the electrodes are composed of materials with high specific surface area and the distance between the electrode and electrochemical double layer is very small compared to standard capacitors.  A variety of porous silicon nanowires have been developed for use as supercapacitors electrodes by maximizing the specific surface area of active materials.  Although the use of Si is attractive due to its wide-spread adoption by microelectronics industry and due to its abundance, Si nanowires are highly reactive and dissolve rapidly when exposed to mild saline solutions.  Previously, silicon carbide thin films were used to protect the porous silicon nanowires, but the coatings were 10’s of nm thick and while they successfully mitigated Si degradation during electrochemical cycling in aqueous electrolytes, they also resulted in pore blockage and a large decrease in energy storage potential.   Researchers at UC Berkeley have developed methods and materials to improve porous silicon nanowires by overcoming the above limitations.  The resulting nanowires have an ultrathin carbon coating preserving the pore structure while mitigating Si degradation.  The resulting supercapacitor electrodes have the highest capacitance (and hence energy storage) per projected area to date.   

The selective and efficient conversion of light alkanes into value-added chemicals remains a challenge for those in the petrochemical and chemical industries.  Currently, there is no go-to commercial process for the selective oxidative conversion of C1-C3 hydrocarbons into value-added chemical feedstocks, such as methanol and ethanol. Industrially, methanol is produced in an indirect and energy intensive process beginning with the steam reformation of natural gas into synthesis gas. After fermentation, ethanol is largely produced from the hydration of ethylene/ethene, which relies on the use of concentrated acids and elevates risk for human safety and environment. To overcome these challenges, researchers at UC Berkeley have devised novel materials and methods involving redox-active metals within porous metal-organic frameworks for driving improved catalytic oxidation of small hydrocarbons to their corresponding alcohols and aldehydes. This innovation could be of special importance to the boom of shale gas processing, which consists of largely methane, but also contains large amounts of ethane and other light alkane impurities.

Berkeley researchers have created an electric fan with visual detection camera and movement recognition software to identify the presence and location of occupants. Occupant tracking algorithm localizes air movements to individualize comfort and conserve energy. The fan can be integrated in ceilings, wall partitions or office furniture.

Researchers at the University of California, Berkeley have designed a reactor cavity, reactor vessel, and core barrel system that has desirable features for use with fluoride salt cooled high temperature reactors (FHRs). The FHRs offer two potential advantages: smaller equipment size, because of the higher volumetric heat capacity of the salts, and the absence of chemical exothermal reactions between the reactor, intermediate loop and power cycle coolants for increased safety. The FHR is a pool type reactor, with a reactor vessel design similar to that commonly used in pool-type sodium fast reactors (SFRs).  General design practice in SFRs is to have a separate guard vessel to maintain the coolant inventory in the primary system if the reactor vessel leaks or ruptures.  This invention uses a different design approach that eliminates the need for a guard vessel. The design also provides useful structures to hold intermediate and emergency cooling heat exchangers and other equipment needed for operation of the reactor.

Underground jacketed and unjacketed power distribution and transmission cables are subject to ongoing deterioration. Furthermore, the concentric neutral (CN) wires in these cables can corrode and break. Power utilities have great interests in determining the condition of CNs -- in situ while they are energized in their normal state. The use of non-magnetic flexible chains to support current sensors enables a single sensing tool to inspect CN currents in underground power cables with various diameters. This approach lowers inspection costs by reducing tool inventories and technician time. To refine this cable inspection approach, researchers at UC Berkeley have developed an inexpensive and safe means of tracking the motion of a CN current sensor during the inspection of high-voltage energized power cables. The Berkeley approach uses off-the-shelf wireless optical mouse systems along with specially developed software to simply, quickly, and safely obtain coordinates of the current sensor movement as the sensing device moves along or circumferentially around the cable under inspection. The software enables the operator to keep the position display automatically within the allowable display area of a computer screen, or to adjust the display parameters for optimal monitoring of the sensor.

With over 100 million tons produced annually, oxygen (O2) is among the most widely used commodity chemicals in the world -- and the demand for pure O2 could grow enormously due to its potential use in processes associated with the reduction of carbon dioxide emissions from fossil fuel-burning plants.   The separation of O2 from air is currently done on a large scale using an energy-intensive cyrogenic distillation process. Zeolites are also used for O2 / N2 separation, however this process is inherently inefficient as the materials used adsorb N2 over O2 with poor selectivity.   To address this situation, researchers at UC Berkeley have developed novel redox-active metal-organic frameworks for gas separation. In comparison to conventional materials, the Berkeley material displays incredible separation properties at temperatures that are much more favorable to those currently used in numerous gas separaton and storage applications.   

Operation of axial or radial turbines under wet conditions is generally avoided because of three performance disadvantages: (1) droplets are unlikely to strike the turbine blades in a way that efficiently converts their momentum to rotor torque; (2) the liquid film that forms on the turbine blades alters the aerodynamics of the flow and makes it challenging to optimize the design for performance; and (3) droplet impingement in conventional turbines can cause the rotor blades to erode, and thereby shorten the life of the turbine. To address this problem, UC Berkeley researchers have developed a turbine design that is optimized for wet operation (i.e. operation with internal flow of liquid and vapor fluid phases). As the replacement for the expansion valve in vapor compression refrigeration and air-conditioning systems, this innovation can significantly enhance the energy efficiency of vapor compression systems by extracting additional power output and increasing the heat absorbing capacity of the refrigerant in the evaporator. Another version of the innovation can be used as the work output turbine in a Rankine cycle power generation system designed for wet turbine operation. This wet expansion cycle design has significantly higher heat input heat exchanger effectiveness, and higher energy efficiency than conventional Rankine cycles with superheat. 

There is strong commercial potential in the use of piezoelectric crystals for AC electricity sensors and in energy scavenging from nearby energized conductors. However, the widespread adoption of piezoelectrics in these applications is predicated on low cost of ownership including long lifecycles that don't require maintenance -- such as replacing batteries or failed parts. Therefore, improving the duration of the no-maintenance lifecycle of this technology strengthens its market potential for broad commercial penetration. To address this opportunity, researchers at UC Berkeley have developed a means of dynamically adjusting the operating properties of piezoelectric crystals used in AC electricity sensing and energy scavenging applications. This dynamic adjustment reduces the fatigue of piezoelectric crystals thereby promoting a longer lifecyle. In addition, the dynamic adjustments are implemented via circuit means -- instead of mechanical means that require relatively substantial power.

To meet the needs of future power generation and distribution, energy storage devices with both high energy and power density are required; a need not met by current super/ultracapacitors which have very high power density, but energy densities one order less than conventional batteries.  Investigators at University of California at Berkeley have taken an innovative approach to meeting these needs by quantum size effects to substantially boost the particle dielectric constant and breakdown strength.  The investigators use a nanoaggregate/composite with a high K and high breakdown strength in the ultracapcitor in order to achieve both high energy and high power density.  The nanocomposite is created by bonding monodisperse core shell nanoparticles with radii <10 nm in a high breakdown strength polymer (ex. PVDF).  This nanocomposite is integrated into a novel, interdigitated electrode configuration to create batch scale manufacturable ultracapacitor cells with equal or superior energy density to that of lithium ion batteries (100 Wh/kg).  This ultracapacitor modules are being developed for multiple applications from powering portable electronics to hybrid vehicles to energy storage for power plants, especially alternative energy storage (solar, wind, etc.).

The invention is about an extremely efficient photodiode and solar cell using a novel nanoneedle structure to create a large internal field for electron-hole amplification and collection, and a plasmonic antenna for optical field enhancement.  Both of which work together to result in an extremely high efficiency. Investigators at UCB have demonstrated one version of this detector in the format of an avalanche photodetector (APD) based upon a crystalline GaAs nanostructure in the shape of a very sharp nanoneedle (NN) and incorporating a core-shell p-n junction for light detection. The tapered NN shape, high NN aspect ratio, and small NN dimension together allow a low bias voltage to produce a high electric field sufficient for current multiplication for high sensitivity. NN APDs also have an extremely high operation speed due to the reduced capacitance comimg from the small NN dimensions. The catalyst-free, low-temperature growth mode of the GaAs NNs also enables the integration to the as-fabricated Si CMOS devices as well as other crystalline or amorphous substrates.