Joseph Steinmeyer | Massachusetts Institute of Technology (MIT) (original) (raw)
Address: Cambridge, Massachusetts, United States
less
Uploads
Papers by Joseph Steinmeyer
Introducing students to Electrical Engineering and Computer Science (EECS) can be difficult to im... more Introducing students to Electrical Engineering and Computer Science (EECS) can be difficult to implement within the limited time constraints often encountered in high school summer programs because of the large amount instruction and theory needed to enable suitably complex projects. Projects of meaningful complexity require carefully balancing how much theory and design is left to the students or provided by the instructor. Here we present a short one-week project-based course developed in the summer of 2011 that introduced rising high school seniors to core concepts in EECS. Three days of instruction and teaching labs were followed by two days where students designed and constructed devices used in creating a solar-powered mobile health clinic. A carefully balanced environment enabled students to progress steadily through the entire process of designing, constructing, and testing their projects. Students then presented their work in a conference-style talk. Details of the course outline, methodology, projects, and results, are presented.
Journal of Micromechanics and Microengineering, 2006
We have designed, fabricated and characterized large displacement distributed-force polymer actua... more We have designed, fabricated and characterized large displacement distributed-force polymer actuators driven only by the surface tension of water. The devices were inspired by the hygroscopic spore dispersal mechanism in fern sporangia. Microdevices were fabricated through a single mask process using a commercial photo-patternable silicone polymer to mimic the mechanical characteristics of plant cellulose. An analytical model for predicting the microactuator behavior was developed using the principle of virtual work, and a variety of designs were simulated and compared to the empirical data. Fabricated devices experienced tip deflections of more than 3.5 mm and angular rotations of more than 330° due to the surface tension of water. The devices generated forces per unit length of 5.75 mN m-1 to 67.75 mN m-1. We show initial results indicating that the transient water-driven deflections can be manipulated to generate devices that self-assemble into stable configurations. Our model shows that devices should scale well into the submicron regime. Lastly, the actuation mechanism presented may provide a robust method for embedding geometry-programmable and environment-scavenged force generation into common materials.
Journal of Micromechanics and Microengineering, 2006
Applied Physics Letters, 2009
Inspired by water transport in plants, we present a synthetic, microfabricated ``leaf'' that can ... more Inspired by water transport in plants, we present a synthetic, microfabricated ``leaf'' that can scavenge electrical power from evaporative flow. Evaporation at the surface of the device produces flows with velocities up to 1.5 cm/s within etched microchannels. Gas-liquid interfaces within the channels move across an embedded capacitor at this velocity, generating 250 ms, 10-50 pF transient changes in capacitance. If connected to a rectified charge-pump circuit, each capacitive transient can increase the voltage in a 100 μF storage capacitor by ~2-5 μV. We provide estimates of power density, energy density, and scavenging efficiency.
Introducing students to Electrical Engineering and Computer Science (EECS) can be difficult to im... more Introducing students to Electrical Engineering and Computer Science (EECS) can be difficult to implement within the limited time constraints often encountered in high school summer programs because of the large amount instruction and theory needed to enable suitably complex projects. Projects of meaningful complexity require carefully balancing how much theory and design is left to the students or provided by the instructor. Here we present a short one-week project-based course developed in the summer of 2011 that introduced rising high school seniors to core concepts in EECS. Three days of instruction and teaching labs were followed by two days where students designed and constructed devices used in creating a solar-powered mobile health clinic. A carefully balanced environment enabled students to progress steadily through the entire process of designing, constructing, and testing their projects. Students then presented their work in a conference-style talk. Details of the course outline, methodology, projects, and results, are presented.
Journal of Micromechanics and Microengineering, 2006
We have designed, fabricated and characterized large displacement distributed-force polymer actua... more We have designed, fabricated and characterized large displacement distributed-force polymer actuators driven only by the surface tension of water. The devices were inspired by the hygroscopic spore dispersal mechanism in fern sporangia. Microdevices were fabricated through a single mask process using a commercial photo-patternable silicone polymer to mimic the mechanical characteristics of plant cellulose. An analytical model for predicting the microactuator behavior was developed using the principle of virtual work, and a variety of designs were simulated and compared to the empirical data. Fabricated devices experienced tip deflections of more than 3.5 mm and angular rotations of more than 330° due to the surface tension of water. The devices generated forces per unit length of 5.75 mN m-1 to 67.75 mN m-1. We show initial results indicating that the transient water-driven deflections can be manipulated to generate devices that self-assemble into stable configurations. Our model shows that devices should scale well into the submicron regime. Lastly, the actuation mechanism presented may provide a robust method for embedding geometry-programmable and environment-scavenged force generation into common materials.
Journal of Micromechanics and Microengineering, 2006
Applied Physics Letters, 2009
Inspired by water transport in plants, we present a synthetic, microfabricated ``leaf'' that can ... more Inspired by water transport in plants, we present a synthetic, microfabricated ``leaf'' that can scavenge electrical power from evaporative flow. Evaporation at the surface of the device produces flows with velocities up to 1.5 cm/s within etched microchannels. Gas-liquid interfaces within the channels move across an embedded capacitor at this velocity, generating 250 ms, 10-50 pF transient changes in capacitance. If connected to a rectified charge-pump circuit, each capacitive transient can increase the voltage in a 100 μF storage capacitor by ~2-5 μV. We provide estimates of power density, energy density, and scavenging efficiency.