Why: Lithium-ion batteries make electric cars possible at mass-market prices.
Key innovation: Nanostructured electrodes result in lithium batteries more durable and safer than those in cell phones and laptops.
Why: The exponential growth in traffic on the Web is possible because of services that route data intelligently.
Key innovation: Its algorithms optimize online routes for content delivery.
Why: E-books are finally becoming a large, mainstream market.
Key innovation: Even as it seeded the e-book market with the Kindle, Amazon has made it easy for people to read e-books on other devices, such as the iPad.
Why: Smart electrical grids and more efficient power cables can help save money and energy.
Key innovation: Underground superconductor power cables using AMSC’s Amperium™ high temperature superconductor wire can carry up to 10 times as much electricity as conventional copper cables.
Why: Advanced biofuels could help reduce the use of gasoline and diesel.
Key innovation: Its genetically engineered yeast turns sugars into a building block of diesel fuel, which is usable in the existing transportation infrastructure.
Why: The rest of the consumer electronics industry is scrambling to catch up to the iPad. The iPhone still sets the standard for smart phones, even if its market share slips.
Key innovation: Its limited lineup of mobile devices all run on the same east-to-use software.
Why: Powerful computing devices are proliferating because of chips that incorporate every-smaller features without rising in price.
Key innovation: its machines can make chips that have both vertical and horizontal connections, to pack in more computing power.
Why: It is redesigning smart phones and tablets so that they'll use much less power and need recharging less often.
Key innovation: Developed energy-efficient customizable chips for mobile devices.
Why: Many doctors and researchers lack the resources to sequence genomes and analyze them themselves.
Key innovation: Sells sequencing as a service, analyzing DNA samples that customers send in.
Why: Embryonic stem cells provide a potential source of replacement tissue for use in treating an array of degenerative diseases and injuries.
Key innovation: Has begun clinical trials for a spinal-cord therapy derived from these cells.
Why: It still sets the agenda in Web search, even as it pushes the development of Android for mobile devices.
Key innovation: Its software development process remains relatively fast even as the company has gotten very big.
Why: Smart phones that run Android have become an alternative to Apple's mobile devices.
Key innovation: Designed well-crafted devices in partnerships with Google and wireless carriers.
Why: Robots can save lives by doing jobs too dangerous for people.
Key innovation: Its small, agile robots can detect and dispose of explosive devices for the military.
Why: Quick, cheap DNA sequencing will lead to new diagnostic test and targeted treatments.
Key innovation: Its desktop gene-sequencing machines costs $50,000, about a 10th as much as other machines.
Why: Inexpensive video on demand, delivered over the Internet, undercuts cable and points the way to a likely future for TV.
Key innovation: Built demand for a streaming video service by including it free with DVD-by-mail subscriptions.
Why: Mainstream use of electric cars could benefit the environment, especially where power is produced relatively cleanly.
Key innovation: Nissan's new electric car, the Leaf, has a reasonably modest sticker price of $32,000.
Why: Understanding molecular pathways of rare diseases can shed light on common ones.
Key innovation: Introduced the first medication for patients with benign brain tumors associated with a particular genetic disorder; now the drug is approved for treatment of kidney cancer and is in testing for other types.
Why: DNA sequencing provides a way to detect microbes in the environment and monitor the spread of viruses in our bodies.
Key innovation:Its sequencing machine can read single strands of DNA in real time.
Why: Drugs that target genetic mutations unique to cancer cells may be more effective than ones that act more broadly.
Key innovation: A new drug blogs the effects of a mutation thought to be present in as many as 8 percent of all cancers.
Why: Hybrid cars can significantly reduce gasoline consumption by using an electric motor alongside a gasoline engine.
Key innovation: A market leader with its Prius model, it is developing battery technologies that are helping to make these cars less expensive and more energy-efficient.