This literature survey, conducted by the Digital Cellulose Center, details sensors and energy harvesting technologies capable of being integrated in, or on, cellulose-based materials such as paper or board. The goal of the survey is to identify how full sensor system integration can be performed on environmentally friendly substrates. Using cellulose and other bio-based materials from the forest is a promising way of making electronics greener. Also, such system integration can add new intelligence to existing cellulose products such as packages for food and logistics. The survey focuses on moisture sensors, temperature sensors, pressure and strain sensors, piezoelectric cellulose, patterning methods, and triboelectric nanogenerators, each one divided into separate chapters. The outcome of the survey is considered in the light of connected cellulose-based sensor applications, identifying the most pertinent scientific questions and remaining challenges. We particularly consider the results in light of sensors integrated into pressboard.