Numerous energy harvesting wireless devices that will serve as building blocks for the Internet of Things (IoT) are currently under development. However, there is still only limited understanding of the properties of various energy sources and their impact on energy harvesting adaptive algorithms. Hence, we focus on characterizing the kinetic (motion) energy that can be harvested by a wireless node with an IoT form factor and on developing energy allocation algorithms for such nodes. In this paper, we describe methods for estimating harvested energy from acceleration traces. To characterize the energy availability associated with specific human activities (e.g., relaxing, walking, cycling), we analyze a motion dataset with over 40 participants. Based on acceleration measurements that we collected for over 200 hours, we study energy generation processes associated with day-long human routines. We also briefly summarize our experiments with moving objects. We develop energy allocation algorithms that take into account practical IoT node design considerations, and evaluate the algorithms using the collected measurements. Our observations provide insights into the design of motion energy harvesters, IoT nodes, and energy harvesting adaptive algorithms.

This article focuses on a new type of wireless devices in the domain between RFIDs and sensor networks—Energy-Harvesting Active Networked Tags (EnHANTs). Future EnHANTs will be small, flexible, and self-powered devices that can be attached to objects that are traditionally not networked (e.g., books, furniture, toys, produce, and clothing). Therefore, they will provide the infrastructure for various tracking applications and can serve as one of the enablers for the Internet of Things. We present the design considerations for the EnHANT prototypes, developed over the past 4 years. The prototypes harvest indoor light energy using custom organic solar cells, communicate and form multihop networks using ultra-low-power Ultra-Wideband Impulse Radio (UWB-IR) transceivers, and dynamically adapt their communications and networking patterns to the energy harvesting and battery states. We describe a small-scale testbed that uniquely allows evaluating different algorithms with trace-based light energy inputs. Then, we experimentally evaluate the performance of different energy-harvesting adaptive policies with organic solar cells and UWB-IR transceivers. Finally, we discuss the lessons learned during the prototype and testbed design process.

Numerous energy harvesting wireless devices that will serve as building blocks for the Internet of Things (IoT) are currently under development. However, there is still only limited understanding of the properties of various energy sources and their impact on energy harvesting adaptive algorithms. Hence, we focus on characterizing the kinetic (motion) energy that can be harvested by a wireless node with an IoT form factor and on developing energy allocation algorithms for such nodes. In this paper, we describe methods for estimating harvested energy from acceleration traces. To characterize the energy availability associated with specific human activities (e.g., relaxing, walking, cycling), we analyze a motion dataset with over 40 participants. Based on acceleration measurements that we collected for over 200 hours, we study energy generation processes associated with day-long human routines. We also briefly summarize our experiments with moving objects. We develop energy allocation algorithms that take into account practical IoT node design considerations, and evaluate the algorithms using the collected measurements. Our observations provide insights into the design of motion energy harvesters, IoT nodes, and energy harvesting adaptive algorithms.

This paper focuses on a new type of wireless devices in the domain between RFIDs and sensor networks - Energy Harvesting Active Networked Tags (EnHANTs). Future EnHANTs will be small, flexible, and self-powered devices that can be attached to objects that are traditionally not networked (e.g., books, toys, clothing), thereby providing the infrastructure for novel tracking applications. We present the design considerations for the EnHANT prototypes, developed over the past 3 years. The prototypes harvest indoor light energy using custom organic solar cells, communicate and form multihop networks using ultralow-power Ultra-Wideband Impulse Radio (UWB-IR) transceivers, and adapt their communications and networking patterns to the energy harvesting and battery states. We also describe a small scale EnHANTs testbed that uniquely allows evaluating different algorithms with trace-based light energy inputs.

The modern computing landscape increasingly requires a range of skills to successfully integrate complex systems. Project-based learning is used to help students build professional skills. However, it is typically applied to small teams and small efforts. In this paper, we describe our experience in engaging a large number of students in research projects within a multi-year interdisciplinary research effort. The projects expose the students to various disciplines in Electrical Engineering (circuit design, wireless communications, hardware prototyping), Computer Science (embedded systems, algorithm design, networking) and Applied Physics (thin-film battery design, solar cell fabrication). While a student project is usually focused on one discipline area, it requires interaction with at least two other areas. Over 4 years, 115 semester-long projects have been completed. The students were a diverse group of high school, undergraduate, and M.S. Computer Science, Computer Engineering, and Electrical Engineering students. Some of the approaches we have taken to facilitate student learning are real-world system development constraints, regular cross-group meetings, and extensive involvement of Ph.D. students in student mentorship and knowledge transfer. To assess our approaches, we conducted a survey among the participating students. The results demonstrate the effectiveness of our methods. For example, 70% of the students surveyed indicated that working on their research project improved their ability to function on multidisciplinary teams more than coursework, internships, or any other activity.

This studio will combine familiar rapid prototyping tools with unfamiliar materials to demonstrate how to fabricate electronic devices. Participants will design and fabricate a laser cut capacitive touch pad and a printed organic light emitting diode (OLED) display that can be combined to create a unique custom game.

Energy Harvesting Active Networked Tags (EnHANTs) are a new class of devices in the domain between RFIDs and sensor networks. EnHANTs will be small, flexible, and energetically self-reliant. Their development is enabled by advances in ultra-low-power ultra-wideband (UWB) communications and in organic semiconductor-based energy harvesting materials. In this demo, we present UWB-enabled EnHANT prototypes. Each prototype is based on a MICA2 mote integrated with a UWB Transceiver and an energy harvesting module (EHM) that allows demonstrating energy harvesting-adaptive communications. Additional information about EnHANTs is available at [2] and http://enhants.ee.columbia.edu.

Energy Harvesting Active Networked Tags (EnHANTs) will be a new class of devices in the domain between RFIDs and sensor networks. Small, flexible, and energetically self-reliant, EnHANTs will be attached to objects that are traditionally not networked, such as books, furniture, toys, produce, and clothing. More information about the EnHANTs project is available at http://enhants.ee.columbia.edu. In this demo we present a small network of EnHANT prototypes. The current EnHANT prototypes are integrated with novel custom in-house-developed energy harvesting and communications hardware, namely organic solar cells and ultra-wide-band impulse radio (UWB-IR) transceivers. The demo showcases prototypes communicating using the novel UWB-IR transceivers and adapting their communications and networking parameters to the available environmental energy harvested by the organic solar cells.

Many interactive systems use "conventional" silicon- based sensors and electronics that limit their functionality and scalability. Organic, amorphous inorganic, and other "unconventional" electronics are ideal for applications that require mechanical flexibility or large-area sensing. In this studio participants will use simple control electronics and a range of unconventional materials to design and build a custom interactive system that combines organic light-emitting diodes and piezoelectric pressure sensors.

Tired of the same old pre-packaged display modules? Does your project need more visual oomph? Then make your own display! In this studio you will learn how to design and build novel, application-specific displays. We will cover the basic operating principles of many popular displays, including electroluminescent displays, liquid crystal displays, vacuum fluorescent displays, and organic light-emitting diode (OLED) displays. We will demonstrate how you can build displays using simple design tools and fabrication techniques. Finally you will design and build your own screen-printed electroluminescent display.