- UCLA researchers create polymer solar cells with higher efficiency levels
By Wileen Wong Kromhout | 11/26/2008
Currently, solar cells are difficult to handle, expensive to purchase and complicated to install. The hope is that consumers will one day be able to buy solar cells from their local hardware store and simply hang them like posters on a wall.
A new study by researchers at the UCLA Henry Samueli School of Engineering and Applied Science has shown that the dream is one step closer to reality. Reporting in the Nov. 26 edition of the Journal of the American Chemical Society, Yang Yang, a professor of materials science and engineering, and colleagues describe the design and synthesis of a new polymer, or plastic, for use in solar cells that has significantly greater sunlight absorption and conversion capabilities than previous polymers.
The research team found that substituting a silicon atom for carbon atom in the backbone of the polymer markedly improved the material’s photovoltaic properties. This silole-containing polymer can also be crystalline, giving it great potential as an ingredient for high-efficiency solar cells.
“With the reality of today’s energy crisis, a new-game changing technology is required to make solar cells more popular,” Yang said. “We hope that our newly synthesized polymer can eventually be used on solar cells far beyond their current rooftop applications. Imagine a house or car covered and powered by flexible solar films. Our dream is to see solar cells used everywhere.”
Polymers are lightweight, low-cost plastics used in packaging materials and inexpensive products like insulators, pipes, household products and toys. Polymer solar cells utilize organic compounds to produce electricity from sunlight. They are much cheaper to produce than traditional silicon-based solar cells and are also environmentally friendly.
But while polymer solar cells have been around for several years, their efficiency has, until recently, been low. The new polymer created by Yang’s team reached 5.1 percent efficiency in the published study but has in a few months improved to 5.6 percent in the lab. Yang and his team have proven that the photovoltaic material they use on their solar cells is one of the most efficient based on a single-layer, low-band-gap polymer.
At a lower band gap, the polymer solar cell can better utilize the solar spectrum, thereby absorbing more sunlight. At a higher band gap, light is not easily absorbed and can be wasted.
“Previously, the synthesizing process for the polymer was very complicated. We’ve been able to simplify the process and make it much easier to mass produce,” said Jianhui Hou, UCLA postdoctoral researcher and co-author of the study. “Though this is a milestone achievement, we will continue to work on improving the materials. Ideally we’d like to push the performance of the solar cell to higher than 10 percent efficiency. We know the potential is there.”
“We hope that solar cells will one day be as thin as paper and can be attached to the surface of your choice,” added co-author Hsiang-Yu Chen, a UCLA graduate student in engineering. “We’ll also be able to create different colors to match different applications.”
The study was funded by Solarmer Energy Inc. and a UC Discovery Grant. Solarmer Energy Inc. has recently licensed the technology from UCLA for commercialization.
The UCLA Henry Samueli School of Engineering and Applied Science, established in 1945, offers 28 academic and professional degree programs, including an interdepartmental graduate degree program in biomedical engineering. Ranked among the top 10 engineering schools at public universities nationwide, the school is home to six multimillion-dollar interdisciplinary research center in space exploration, wireless sensor systems, nanotechnology, nanomanufacturing and nanoelectronics, all funded by federal and private agencies. For more information, visit http://www.engineer.ucla.edu.
- farming and horticulture
Robots are on the march again into the last bastion of labour intensive industry – farming and horticulture. Warwick researchers are working on a suite of robots and automated systems which could transform farming and horticulture over the next decade.
The researchers from the University of Warwick’s horticultural arm, Warwick HRI, and its manufacturing engineering section, Warwick Manufacturing Group, are working on a number of robotics and automation products that will vastly reduce the labour costs of farmers and growers. Those projects include:
A robotic mushroom picker: the robot uses a charged coupled camera to spot and select only mushrooms of the exact size required for picking achieving levels of accuracy far in excess of human labour. The mushroom(s) are then picked by a suction cup on the end of a robotic arm. Whilst the speed of picking is currently just over half that of a human – the mushrooms and the robot can be set to pick 24 hours a day right through the night without the need for any sort of break. The researchers also hope to increase the speed of picking to much closer to that of a human worker.
Inflatable Conveyor Belt: The Warwick Manufacturing Group and Warwick HRI researchers have helped an agricultural machinery company “Aeropick” to develop a revolutionary group of inflatable aids to harvesting which provide huge savings on labour costs. The inflatable conveyor system can be driven into an open field or covered growing area. Within minutes up to 100 metres of powered conveyor belt can be deployed allowing crops to be processed at high speed straight to cool storage, or washing, or simply sorted and graded while still in the field.
Robot Grass Cutter: Mowing the lawn is a drudge but for growers, farmers, even golf course owners, with large amounts of grass land it’s a massive problem with every tractor requiring a skilled employee to manage such pastures. Researchers in the Warwick Manufacturing Group are developing a new method which can allow a farmer or grower to deploy multiple robotic grass cutting machines at the same time all under the supervision of just a single employee. They are working with the “Ransomes Spider” grass cutting device which can already be remotely controlled and can even mow on 40 degree inclines. They are replacing that remote control with a computer that can use its own data sensors attached to the mower, to autonomously travel across fields working in groups with other robotic mowers ensure that the field is mowed as quickly as possible.
Peter Dunn, Press and Media Relations Manager
University of Warwick 02476 523708 or 07767 655860
Wageningen UR Greenhouse Horticulture has secured European subsidy for “Efficient use of input in Protected Horticulture
10 Jul 2008
Unit: Wageningen UR Glastuinbouw
Wageningen UR Greenhouse Horticulture has secured European subsidy for “Efficient use of input in Protected Horticulture
In 4 years WUR Greenhouse Horticulture and 10 partners, with 3 M€ subsidy from the EU, will develop a milieu-friendly and financially sound greenhouse. The aim is a cultivation system relying only on sustainable energy, with minimal “carbon footprint”, devoid of emissions and thrifty with water and substrates.
Besides nearly all teams of Wageningen UR Greenhouse Horticulture, the consortium includes Universities and Research Centers from Great Britain, Spain and Italy, as well as commercial firms dealing with greenhouse covers, recycling of substrates, monitoring and management systems (HortiMax), and also a growers’ cooperative from Hungary.
Use of renewable energy sources
Zero emissions of water and chemicals, sustainable recycling of substrates
Decrease reliance on Plant Protection Chemicals
Monitor and management tools
Assessing environmental impact and financial soundness
Integration and evaluation
The project, whose acronym is EUPHOROS, is divided into “work packages”, whose specific goals are shown in the table. Being the coördinator of the project, Wageningen UR Greenhouse Horticulture will be involved in nearly all work packages. Our most important contribution will be in the development of “soft sensors” to monitor the large scale performance of the greenhouse and of the crop (such as with the “ventilation monitor”) and in the application of innovative “smart sensors” for the small scale early detection of biotic/abiotic stress.
Even an incremental adoption by the growers of the project results will increase competitiveness
while reducing resource use of the European greenhouse production. A truly continental impact will be achieved by developing systems that are anchored in the local speciality of greenhouse industries and which are seen to respond to the diversity of climatic, economic and environmental constraints across Europe. This will be ensured by installing, testing, fine-tuning and evaluating locally relevant combinations of crops (tomato and/or rose), equipment, covering materials, cultivation techniques, monitoring and control systems in The Netherlands, Spain and Hungary.
The involvement of local stakeholders to give feed-back, and extended dissemination activities, like national & international workshops and a training course, are included to ensure the convergence of project results with market expectations and acceptance.
Dr Cecilia Stanghellini
- robots show that brain activity is linked to time as well as space
Humanoid robots have been used to show that that functional hierarchy in the brain is linked to time as well as space. Researchers from RIKEN Brain Science Institute, Japan, have created a new type of neural network model which adds to the previous literature that suggests neural activity is linked solely to spatial hierarchy within the animal brain. Details are published November 7th in the open-access journal PLoS Computational Biology.
An animal’s motor control system contains a functional hierarchy, whereby small, reusable parts of movements are flexibly integrated to create various action sequences. For example, the action of drinking a cup of coffee can be broken down into a combination of small movements including the motions of reaching for a cup, grasping the cup, and bringing it to one’s mouth.
Earlier studies suggested that this functional hierarchy results from an explicit spatial hierarchical structure, but this has not been seen in anatomical studies of the brain. The underlying neural mechanisms for functional hierarchy, thus, had not yet been definitively determined.
In this study, Yuichi Yamashita and Jun Tani demonstrate that even without explicit spatial hierarchical structure a, functional hierarchy can self-organize through multiple timescales in neural activity. Their model was proven viable when tested with the physical body of a humanoid robot. Results suggest that it is not only the spatial connections between neurons, but also the timescales of neural activity, that act as important mechanisms in neural systems.
Yamashita Y, Tani J. Emergence of Functional Hierarchy in a Multiple Timescale Neural Network Model: A Humanoid Robot Experiment. PLoS Comput Biol, 2008; 4(11): e1000220 DOI: 10.1371/journal.pcbi.1000220 Lab. for Behavior and Dynamic Cognition
RIKEN Brain Science Institute
2-1 Hirosawa, Wako, Saitama, 351-0198 Japan
- carnegie mellon developing automated systems to enable precision farming of apples, oranges
PITTSBURGH—Two groups of researchers at Carnegie Mellon University’s Robotics Institute have received a total of $10 million in grants from the U.S. Department of Agriculture (USDA) to build automated farming systems. One is for apple growers and one is for orange growers, but both are designed to improve fruit quality and lower production costs.
The systems use sensors on autonomous robotic vehicles or at fixed sites within the orchards to gather a multitude of data about tree health and crop status. Robotic vehicles will be used to administer precise amounts of water or agricultural chemicals to specific areas or trees. The vehicles also will be used to automate routine tasks such as mowing between tree rows.
The projects were funded this fall through the USDA’s new Specialty Crop Research Initiative. The Comprehensive Automation for Specialty Crops (CASC) Program, led by Sanjiv Singh, research professor of robotics, received a four-year, $6 million grant to develop systems for the apple industry. The Integrated Automation for Sustainable Specialty Crop Farming Project, led by Tony Stentz and Herman Herman of the Robotics Institute’s National Robotics Engineering Center (NREC), received a three-year, $4 million grant to develop systems for the citrus industry. Both project grants will be matched dollar for dollar by industry, state governments and other funding sources.
“We are taking automation to a level never before demonstrated in an agricultural setting,” said Herman of the NREC project. “This will provide an early look at how the automated farm may someday operate and promises to deliver insights and lessons far beyond what should be expected from small demonstrations of autonomous scouts.”
“Mobile sensors and computer tracking will enable growers to monitor their orchards in unprecedented detail,” said Singh. “Growers will receive early warning of diseases and insect infestations, as well as continuous updates on crop status. With this information, growers can make timely decisions that will save them money and improve the quality of their crop.”
Although Carnegie Mellon is not a university traditionally associated with agricultural research, the Robotics Institute’s Field Robotics Center has been involved in agricultural automation since the early ’90s and the NREC has worked with agricultural equipment manufacturers since it opened in 1996. Moreover, both organizations are experienced in managing research programs involving academic, industrial and governmental researchers working closely with end users.
“This level of collaboration between academia, government and industry is not at all common in agriculture research,” said Jim McFerson, manager of the Washington Tree Fruit Research Commission. The technologies developed will be applicable not only to apple and orange growers, but to producers of all kinds of tree fruits, he added.
“Growers can use the data generated by this new approach to make decisions throughout the year regarding pest management, pruning, fertilization, irrigation and yield estimates,” McFerson said. “We believe this will result in higher quality fruit at a lower per unit cost, as well as a more productive and safer workplace.”
The CASC Program will work with apple growers in Pennsylvania, Oregon and Washington and includes collaborators from Penn State, Washington State, Oregon State and Purdue universities as well as the USDA Agricultural Research Service. Researchers will use a fleet of automated four-wheel vehicles that can perform multiple tasks, including tree monitoring and chemical spraying. Industrial partners include Toro, Trimble, Vision Robotics, IONco and Sensible Machines.
The NREC’s Integrated Automation for Sustainable Specialty Crop Farming Project will deploy a fleet of networked, unmanned tractors in the orange groves of Southern Gardens Citrus (SGC), one of Florida’s largest growers. In addition to SGC, collaborators include researchers at the University of Florida, Cornell University and Deere & Co.
Harvesting remains one of the most labor-intensive operations at orchards, but it also is very challenging to automate because of demanding handling and cost requirements. Both projects will investigate new designs for mechanical harvesters, including a vacuum-assisted device that the CASC will use for apple harvesting, but the emphasis will be on aiding human harvesters, rather than replacing them.
The Specialty Crop Research Initiative was established by the 2008 Farm Bill to solve critical issues facing specialty crops, which include fruits and vegetables. The two Carnegie Mellon-led projects were among 18 that received a total of $28 million in the first round of grants this fall.
The Robotics Institute is part of Carnegie Mellon’s School of Computer Science.
“everything you see depends on a frame of reference. systems within a system. every move, every flicker, a blink, a blip, a shimmer, life in the passing.”
“certainly sounds impressionistic.”
“like lilies in a pond, water lilies.”
“you mean like fishes?”
“no, what i mean is a world in microcosm.”