Miasole, a Santa Clara, Calif.-based maker of CIGS thin-film photovoltaic solar panels, has raised $55 million in new VC funding. No investor information was disclosed. The company previously raised over $400 million from firms like Kleiner Perkins Caufield & Byers, Firelake Capital Management, Nippon Koatsu Electric Co., VantagePoint Capital Partners, Garage Technology Ventures, Atlas Venture and ArcelorMittal. www.miasole.com

Aragon Pharmaceuticals, a San Diego-based drug developer focused on prostate and other cancers, has raised $42 million in Series C funding. Topspin Fund led the round, and was joined by return backers Aisling Capital, OrbiMed Advisors and The Column Group. The company previously raised $30 million. www.aragonpharm.com

Sequent Medical Inc., an Aliso Viejo, Calif.-based developer of catheter-based technologies for neurovascular patients, has raised $26 million in Series C funding. Delphi Ventures led the round, and was joined by return backers Versant Ventures, US Venture Partners and Domain Associates.www.sequentmedical.com

Virdia (f.k.a. HCL CleanTech), a Redwood City, Calif.-based developer of cellulosic sugars, has raised $20 million in new VC funding from existing backers Khosla Ventures, Burrill & Company and Tamar Ventures. The company also has secured $10 million in venture debt from Triple Point Capital and signed a $75 million with the Mississippi Development Authority to build manufacturing plants in the state. www.virdia.com

OpGen Inc., a Gaithersburg, Md.-based whole-genome analysis company, has secured up to $17 million in new venture capital commitments. Harris & Harris Group and Cross Creek Capital were joined by return backers Highland Capital Partners, Versant Ventures, jVen Capital and CHL Medical Partners.www.opgen.com

Quotient Biodiagnostics Holdings Ltd., a Scotland-based provider of transfusion diagnostics, has raised $11.2 million in growth equity funding led by Galen Partners. www.quotientbd.com

NLT Spine, an Israeli developer of minimally-invasive spinal surgery products, has raised $5.7 million in new VC funding from existing backers Accelmed and Peregrine Ventures. www.nlt-spine.com

BlogFrog, a Boulder, Colo.-based social activation platform for brand marketers, has raised $3.2 million in Series A funding. Grotech Ventures led the round, and was joined by seed backers like David Cohen.www.blogfrog.com

Houston Medical Robotics Inc., a developer of image-guided hand-held medical robotics for use in various therapeutic applications, has raised $2.2 million in Series A funding from CitareTX Investment Partners.

SignNow, a Newport Beach, Calif.-based iPad app for signing documents, has raised $2 million in Series A funding from backers like Khosla Ventures. www.signnow.com

PlayMob, a UK-based provider of gamified fundraising solutions for nonprofits, has raised £500,000 in seed funding from firms like NESTA and Midven. www.playmob.com

Spotflux, a New York-based Internet connection app, has raised $1 million in first-round funding from New Atlantic Ventures and Kima Ventures. www.spotflux.com

Mersive, a Denver-based provider of visual computing software that creates and manages high-performance displays, has received a “multi-million dollar investment” from Razor’s Edge Ventures.www.mersive.com

Roku, a Saratoga, Calif.-based Internet TV platform, is seeking to raise up to $50 million in new funding, according to Bloomberg. The company previously raised around $22 million from firms like Globespan Capital Partners and Menlo Ventures. www.roku.com

Want deal news in your inbox each morning? Then get Term Sheet!