The popularity of Internet of Things (IoT) devices (without tradition human-computer interfaces) has made gesture recognition an advantageous form of human-computer interaction - especially in smart home applications. However, conventional gesture recognition approaches have issues that limit their pervasive use. For example, wearable devices (e.g. watches and wristbands) with inertial sensors can be inconvenient to always wear; radio frequency systems are cost prohibitive for large-scale deployment; and vision-based systems require favorable lighting and introduce privacy concerns. Recently, WiFi infrastructure, and associated WiFi-enabled mobile and IoT devices have become ubiquitous, and correspondingly, have enabled many context-aware and location-based services. To address the opportunities for gesture recognition and take advantage of the popularity of WiFi, researchers at UC Berkeley developed a gesture recognition system based on analyzing signals from existing WiFi-enabled devices. This novel WiFi-enabled, device-free gesture recognition system can identify human gestures with consistent high accuracy and has robust environmental dynamics.

In our electronically connected society, human identification systems are critical to secure authentication, and also enabling for tailored services to individuals. Conventional human identification systems, such as biometric-based or vision-based approaches, require either the deployment of dedicated infrastructure, or the active cooperation of users to carry devices. Consequently, pervasive implementation of conventional human identification systems is expensive, inconvenient, or intrusive to privacy. Recently, WiFi infrastructure, and associated WiFi-enabled mobile and IoT devices have become ubiquitous, and correspondingly, have enabled many context-aware and location-based services. To address the challenges of human identification systems and take advantage of the popularity of WiFi, researchers at UC Berkeley developed a human identification system based on analyzing signals from existing WiFi-enabled devices. This novel device-free approach uses WiFi signal analysis to reveal the unique, fine-grained gait patterns of individuals as the "fingerprint" for human identification.

Water is a scarce resource in some part of the United States, and recent droughts in the Midwest and the South have elevated the issue of water scarcity to a national level. Existing water sources will face increasing strain due to population growth and climate change, and financial and regulatory barriers will prevent the development of new sources. One method to alleviate water scarcity is storm water capture. Storm water can be used for non-potable applications such as irrigation, laundry, and toilet flushing to significantly reduce domestic municipal water consumption. However, in arid regions of the US, rain comes in short, intense storms only a few months out of the year, and the duration and intensity of these storms require large storage tank volumes for storm water capture to be financially feasible.    One solution is to integrate storm water capture with greywater capture. Greywater is a reliable source of water for domestic reuse, and includes water from washbasins, laundry, and showers (kitchen sinks and water for toilet flushing are considered blackwater). Combining greywater-storm water in the same collection system allows for a much smaller storage tank. A UC Berkeley researcher, along with other researchers, have developed aforecast-integrated automated control system for combined greywater-storm water storage and reuse. A simple and reliable approach for managing greywater and storm water collection at a household or community level is provided, allowing for the near-continuous monitoring and adjustment of water quantity and quality in a combined greywater-storm water storage tank based on monitored feedback/output from individual, tank-specific sensors and/or sensors located elsewhere in the water collection system.   

96 Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Endocrine disrupting compounds are found in increasing amounts in our environment, originating from pesticides, plasticizers, and pharmaceuticals, among other sources. These compounds have been implicated in diseases such as obesity, diabetes, and cancer. The list of chemicals that disrupt normal hormone function is growing at an alarming rate, making it crucially important to find sources of contamination and identify new compounds that display this ability. However, there is currently no broad-spectrum, rapid test for these compounds, as they are difficult to monitor because of their high potency and chemical dissimilarity.   To address this, UC Berkeley researchers have developed a new detection system and method for the sensitive detection of trace compounds using electrochemical methods.  This platform is both fast and portable, and it requires no specialized skills to perform. This system enables both the detection of many detrimental compounds and signal amplification from impedance measurements due to the binding of bacteria to a modified electrode. The researchers were able to test the system finding sub-ppb levels of estradiol and ppm levels of bisphenol A in complex solutions. This approach should be broadly applicable to the detection of chemically diverse classes of compounds that bind to a single receptor.  

Conventional chemical sensors or chemical resistors detect the molecule concentration by monitoring the resistance change caused by the reaction near the sensing material surface. One of the problems with these systems is with drift, when over time the analyte molecules poison the device’s sensing surface, causing weaker performance on selectivity and sensitivity. This often requires rigorous and timely calibrations to the sensor, which involves human intervention, and often times complete sensor replacement. To address this problem, researchers at the University of California, Berkeley, have developed a vertical platform that dramatically improves the sensor’s ability to manage and recover from the poison environments. By examining and manipulating the sensing plane vis-à-vis the near field surface, researchers have demonstrated an effective and robust chemical sensing platform for a range of gas sensing applications.

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.

96 Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Calibri; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Structural health monitoring (SHM) is becoming critical in structural engineering and geotechnical engineering applications in recent years. The use of fiber optic distributed sensors for SHM has the advantage of long sensing distance, distributed sensing information and small size.  Distributed fiber optic sensors can be used to monitor distributed temperature and strain information but also has application for used in detection of seismic activity, security sensing, and traffic/railway/bridge monitoring.   UC Berkeley researchers have developed methods and sensors for distributed dynamic strain measurement using optical fiber that results in a larger sensing signal, better signal-to-noise ratio and longer sensing distance up to a few km lengths. The system can take strain readings at every 4m along an 1km length optical fiber at 2.5 kHz sampling speed with a strain resolution of 30 microstrain.  

Realizing the potential of massive sensor networks requires overcoming cost and power challenges. When sleep/wake strategies can adequately limit a network node's sensor and wireless power consumption, then the power limitation comes down to the real-time clock (RTC) that synchronizes sleep/wake cycles. With typical RTC battery consumption on the order of 1µW, a low-cost printed battery with perhaps 1J of energy would last about 11 days. However, if a clock could bleed only 10nW from this battery, then it would last 3 years. To attain such a clock, researchers at UC Berkeley developed a mechanical circuit that harnesses squegging to convert received RF energy (at -58dBm) into a local clock while consuming less than 17.5nW of local battery power. The Berkeley design dispenses with the conventional closed-loop positive feedback approach to realize an RCT (along with its associated power consumption) and removes the need for a sustaining amplifier altogether. 

Piezoelectric Micromachined Ultrasonic Transducers (pMUTs) have attracted industry attention for their good acoustic matching, small geometry, low cost-by-batch fabrication, and compatibilities with CMOS and consumer electronics. While planar pMUTs have reasonable performance over bulk piezoelectric transducers, certain deficits remain in terms of coupling and acoustic pressure outputs, DC displacements, bandwidth, and power consumption. To address these deficiencies, researchers at the University of California, Berkeley, have developed a next generation of shaped pMUTs which are no longer fully defined by resonance frequency and can accommodate larger pressure outputs and bandwidths. This new pMUT apparatus can significantly boost overall performance while dramatically reducing power as compared to flat diaphragm state-of-the-art pMUTs.

Airborne particulates (such as vehicle exhaust, dust, and metallics) are a health hazard.  Monitors for measuring particulate matter (PM) concentrations in air are typically designed for stationary industrial use; and while they are quite sensitive, they are also bulky, heavy, and expensive.  Accordingly, there is a need for PM concentration monitors that are inexpensive and portable so that they can be more pervasive, and also used by mass-market consumers. Recently, various types of portable PM monitors have been developed.  One class of monitor uses optical technology to measure particulates flowing through (not deposited on) the device.  This optical technology is not sensitive to extremely small particles (with diameters of 200 nanometers or less), yet these small particles are a serious health hazard.  Another class of PM monitor uses various technologies to measure the mass of particles deposited on (not flowing through) the device.  This type of monitor can be quite sensitive, but eventually, it can become overloaded with deposited particles.  Moreover, multiple layers of particles can eliminate the possibility of determining the chemical nature of the particles. To address these shortcomings, researchers at UC Berkeley have developed a means of periodically cleaning deposited particles from mass-sensing components of deposit-based PM sensors.  The Berkeley technology results in PM sensors that are not only portable and low-cost, but also have long-lasting functionality.

The use of electric fields for signaling and manipulation is widespread, mediating systems spanning the action potentials of neuron and cardiac cells to battery technologies and lab-on-a-chip devices. Current FET- and dye-based techniques to detect electric field effects are systematically difficult to scale, costly, or perturbative. Researchers at the University of California Berkeley have developed an optical detection platform, based on the unique optoelectronic properties of two-dimensional materials that permits high-resolution imaging of electric fields, voltage, acidity, strain and bioelectric action potentials across a wide field-of-view.

Earthquakes are unpredictable disasters. Earthquake early warning (EEW) systems have the potential to mitigate this unpredictability by providing seconds to minutes of warning. This warning could enable people to move to safe zones, and machinery (such as mass transit trains) to be slowed or shutdown. The several EEW systems operating around the world use conventional seismic and geodetic network infrastructure – that only exist in a few nations. However, the proliferation of smartphones – which contain accelerometers that could potentially detect earthquakes – offers an opportunity to create EEW systems without the need to build expensive infrastructure. To take advantage of this smartphone opportunity, researchers at the University of California, Berkeley have developed a technology to allow earthquake alerts to be issued based on detecting earthquakes underway using the sensors in smartphones. Called MyShake, this EEW system has been shown to record magnitude 5 earthquakes at distances of 10 km or less. MyShake incorporates an on-phone detection capability to distinguish earthquakes from every-day shakes. The UC Berkeley technology also collects earthquake data at a central site where a network detection algorithm confirms that an earthquake is underway as well as estimates the location and magnitude in real-time. This information can then be used to issue an alert of forthcoming ground shaking. Additionally, the seismic waveforms recorded by MyShake could be used to deliver rapid microseism maps, study impacts on buildings, and possibly image shallow earth structure and earthquake rupture kinematics.

To-date, plasmon detection methods have been utilized in the life sciences, electrochemistry, chemical vapor detection, and food safety. While passive surface plasmon resonators have lead to high-sensitivity detection in real time without further contaminating the environment with labels. Unfortunately, because these systems are passively excited, they are intrinsically limited by a loss of metal, which leads to decreased sensitivity. Researchers at the University of California, Berkeley have developed a novel method to detect distinct molecules in air under normal conditions to achieve sub-parts per billion detection limits, the lowest limit reported. This device can be used detecting a wide array of molecules including explosives or bio molecular diagnostics utilizing the first instance of active plasmon sensor, free of metal losses and operating deep below the diffraction limit for visible light.  This novel detection method has been shown to have superior performance than monitoring the wavelength shift, which is widely used in passive surface plasmon sensors. 

Conventional chemical sensor discriminates different analytes by rejecting the interference using selective decorations on the sensor body. A cross-reactive chemical sensor array discriminates different analytes by interpreting the collective sensor response using signal processing technique, and solves for the interference. Commercial sensor manufacturers search for the optimal choice of material, identifier and the signal processing technique to maximize the sensor performance in terms of chemical detection and discrimination. To address the need, researchers at the University of California, Berkeley, have developed a platform with 2D material incorporated in a cross-reactive field effect transistor (FET) sensor array. By examining and manipulating the properties of the sensor array, researchers have invented a low power, high efficiency, and versatile chemical sensing technology that is promising for commercialization.

Piezoelectric Micromachined Ultrasonic Transducers (pMUTs) have attracted industry attention for their good acoustic matching, large bandwidth, miniaturization, and low cost-by-batch fabrication. pMUTs have the advantages of low power consumption and large deflection for high-acoustic power applications. However, low electromechanical coupling has been a serious drawback for pMUT applications, in some cases foreclosing key opportunities. In response to this challenge, researchers at UC Berkeley have developed a bimorph pMUT with unique advantages which dramatically improve the device capabilities: the bimorph pMUT utilizing two active AlN layers in a CMOS-compatible process. This innovative design is the first bimorph pMUT with two active piezoelectric layers separated by a common electrode. The prototype bimorph pMUT has a resonant frequency of 198.8 kHz and central displacement of 407.4 nm/V. Under the differential drive scheme using the dual electrodes at low frequency, the measured central displacement is 13.0 nm/V, which is about 400% higher than that of a unimorph AlN pMUT. This revolutionary dual electrode bimorph pMUT presents a new class of design/fabrication for exciting pMUT applications, including range finders and gesture recognition devices.

Curved pMUTs, as developed at UC Berkeley, have been shown to have 2 orders of magnitude improvement over flat pMUTs as well as the capacity for post-processing tuning. However, it is desirable to improve production methods to make this innovation more commercially applicable.To meet this challenge, investigators at Berkeley have developed a self-curved diaphragm process using stress engineering to produce highly responsive curved pMUTs. This diaphragm pMUT can boost 6X better performance compared to the flat diaphragm state-of-the-art pMUT. CMOS foundry-based process flow has produced self-curved diaphragms by engineering residual stress in thin films to construct molds for fabrication. Benefits of the invention include achieving silicon curved molds by patterning thin layers of stressed silicon nitride and silicon oxide layers on top of a silicon plate of a predetermined thickness.

Microfluidic technologies have demonstrated great potential in a wide variety of fields, providing accurate and reliable management of small samples and reagents. Healthcare is particularly well-positioned to benefit from this technology with an ongoing rise in demand for point-of-care (POC) health technologies, including concepts such as lab-on-a-chip (LOC). Despite their promise, these LOC devices have not been widely commercialized or adopted primarily because of the critical transition from an initial research design into a final product. To overcome this challenge, differences in the fabrication methods used in the research process and in final industrial production need to be eliminated.To meet this challenge, investigators at UC Berkeley have made a groundbreaking development creating microfluidic devices in plastics, bridging the fabrication process from lab to commercial manufacturing. Utilizing hot embossing, a new fabrication methodology has been developed for embedding metallic microelectrodes in thermoplastic microfluidic devices. Microelectrodes are first fabricated on steel wafers by means of photolithographic techniques and electrode position, and then transferred to the plastic using hot embossing. The unique shape of the microelectrodes provides self-anchoring mechanisms that ensure structural stability and reliability of the devices. A wide variety of thermoplastics can be used in this process, including polycarbonate, polymethylmethacrylate, cyclic olefin copolymer, and others. Moreover, this technique can be combined with embedded silicon-based sensors providing the necessary connectronics and access to the miniaturized biological or physical sample. With this rapid fabrication method for microfluidic prototypes it is possible to scale the fabrication to a large series of devices easily, shortening the transition of current research to commercial microfluidic devices and revolutionizing current production practices.

Conventional metal-oxide semiconductor field-effect transistor (MOSFET) technology consists of a source, drain, gate, and substrate. The chemical field-effect transistor (chemFET) is a type of a field-effect transistor acting as a chemical sensor, and is similar to MOSFET except for the gate structures. Modern industrial players seek higher-sensitivity technologies which are small, durable, efficient, and versatile. Further advances in these materials and structures could enable many new kinds of layered semiconductors and devices. To address need, researchers at the University of California, Berkeley, have developed chemical-sensitive field-effect transistor (CS-FET) platform technology. By exploiting selective thin films incorporated into the CS-FET, researchers have created chemical sensors with commercial promise in terms of chemical-versatility and low-power. 

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.

Ammonia is used in many industrial and commercial applications, for example in the manufacture of fertilizers and cleaners.  However, ammonia is toxic at high concentrations and, therefore, safe storage and transportation of ammonia is required. In addition, trace amounts of ammonia in the atmosphere contaminate and interfere with certain industrial processes, such as semiconductor fabrication, which requires ultra-pure air. Proper ammonia management includes the adsorption of the gas under each of these pressure regimes: high-pressure adsorption for safe storage and transportation and low-pressure adsorption for the removal of trace contaminants from the ambient air. Current methods of adsorption include simple salts, such as MgCl2, but these are not efficient for low-pressure adsorption and furthermore their ammonia cycle is inefficient, requiring significant heat exchange and large changes in volume. Investigators at UC Berkeley have developed a novel polymer for ammonia adsorption that uses acidic materials placed in a spatial arrangement that allows for cooperative adsorption. This not only increases the efficiency of adsorption but also is effective at both high-pressure and low-pressure ammonia adsorption, resulting in multiple applications of the technology. 

In recent years, gas sensors for industrial applications have experienced great advances through rapid evolution of microelectromechanical systems (MEMS). As a result of increased government legislative pressure on industrial health and safety, commercial customers are demanding integrated smart sensor technology and systems which leverage MEMS for small footprint, low cost, and high-performance features. Market researchers suggest double-digit compound annual growth rates for MEMS sensors through 2018, with the fastest growth is expected in the semiconductor sensor base. Traditional infrared gas analyzers determine the absorption of an emitted infrared light source through a certain air sample. Nondispersive infrared technology (NDIR) detects certain gas by detecting the absorption of infrared wavelengths that is characteristic of that gas. NDIR detectors are the industry standard method of measuring the concentration of carbon oxides. Researchers at UC Berkeley and Davis have successfully demonstrated pyroelectric infrared detectors that exhibit high sensitivity and reliable performance for advanced gas analyses. The MEMS technology is well suited for constant monitoring in harsh environments where long term stability is important, such as petroleum, medical, and industrial monitoring settings.

Sensing and quantifying ions in liquid is important in many research and commercial applications. For instance, pH is often a key component in manufacturing. In biology, sensing ions in solution, such as lab-on-a-chip applications, can be pivotal to an effective application. In many of these technology areas, miniaturization and low cost production of ion sensors is critical.To address this challenge, investigators at University of California at Berkeley have developed a MEMS nanowire ion sensor. This sensor employs a MEMS device where ions are sensed with nanowires using an alternating current (AC) electric field. The MEMS nanowire ion sensor can serve as a chemical sensor. By example, the MEMS nanowire ion sensor can be employed as a pH sensor or pH monitor for environment, infrastructure or plant facility. In biologic applications, the MEMS nanowire ion sensor can serve as a biosensor for biomolecule detection, DNA sequences, blood testing, and an ion species identifier, among others. 

There is a long-standing problem of how to switch piezoelectric filters when used in switchable filter banks -- such as needed in RF channel-selection. To address this problem, researchers at UC Berkeley have developed a method and structure for a piezoelectric resonator with tunable transfer function -- i.e. tunable gain. This Berkeley resonator's gain is tunable to many values -- including values that are low enough to consider the device to be "off" relative to the background signal. Accordingly, this approach enables on/off switching of piezoelectric resonators; and it thereby obviates the need for separate low loss switches, which otherwise would be needed in series with piezoelectric resonators to switch them on and off -- adding insertion loss and raising system gain. In addition, this ability to adjust filter gain makes it possible for the resonator to control low power gain in a receiver front-end.

The reduction of power supply voltage with each new generation of CMOS technology continues to complicate the design of charge pumps needed for high voltage applications that integrate into systems alongside transistor chips -- such as the increasing number of MEMS-based gyroscopes, timing oscillators, and gas sensors. Moreover, the aggressive scaling in CMOS resulting in lower dielectric and junction breakdown voltages has compelled the use of customized CMOS processes -- including increased gate oxide thickness and/or added deep-n-wells. Clearly, advances in transistor technology are moving in the opposite direction of the needs of high voltage MEMS applications. To address this trend, researchers at UC Berkeley have developed a MEMS-based charge pump. This design avoids the turn-on voltage and breakdown limitation of CMOS. With much higher breakdown voltages than transistor counterparts, the demonstrated MEMS charge pump implementation should eventually allow voltages higher than 50V desired for capacitive-gap transduced resonators that currently dominate the commercial MEMS-based timing market.

There is growing interest in ubiquitous monitoring of the ambient atmosphere indoors and outdoors. To address this opportunity, low-cost, fixed and portable particulate monitors are under development. UC Berkeley researchers developed a portable particulate monitor. That patent pending device samples the ambient atmosphere and measures the mass of particles. UC Berkeley researchers have expanded the functionality of that portable device to include the analysis and identification of particles that it senses. The enhanced device can also clean itself of particles and thereby extend its operating life. The Berkeley monitor can determine the concentration of particles in the ambient air such as particles produced from combustion, emission or distribution of bioaerosols, bacterial aerosols, allergens (i.e. pollen), and gaseous pollutants. It could therefore could be used to alert users to the presence of allergens, particles that are harmful to inhale (i.e. silica), as well as toxic or explosive gases. In addition to portable applications, these devices could be permanently installed in buildings, HVAC systems and forced-air furnaces.