2017 UCB-HBCU Program Participants and Projects
Undergraduate Researcher: Chelsea Conaway
Major: Computer Engineering Technology
Home Institution: Prairie View A&M University
Research Project: The Developing Low-Cost Closed-Loop Actuator
HBCU Faculty Advisor: Dr. Paul Potier
UCB Faculty Advisor: Dr. Ana Arias
Mentor: Dr. Kartik Gopalan
Abstract: Actuators are mechanical devices that provide movement or positioning that are operated electrically, manually, or by fluid. The use of closed-loop control to improve performance with 3D printers is a current area of research. Adding the needed sensors and hardware to a low-cost 3D printer has been too expensive to manufacture. Currently, open-loop actuators are less expensive but are more inaccurate due to the lack of positional feedback. The capability to recognize and rectify skipped steps while the machine is running builds reliability within the product and cuts down on production time due to printing errors. The actuator will use off the shelf electronics for linear feedback, a stepper motor, and a low-cost ball screw. This research, if successful, aims to develop a low – cost closed-looped actuator that improves the reliability and performance of various machines at a lower price point.
Project Poster: Link
Undergraduate Researcher: Travion Capers
Major: Electrical Engineering
Home Institution: Norfolk State University
Research Project: Direct Spin Detection in Heavy Metals Using Picosecond Current Pulses
HBCU Faculty Advisor: Dr. Demetris Geddis
UCB Faculty Advisor: Dr. Jeff Bokor
Mentor: Akshay Pattabi
Abstract: A charge current through a heavy metal with strong spin orbit coupling can generate spin current flowing opposite to the applied charge current. These polarized spinning electrons will accumulate on the surfaces of the metal with opposite spin orientation on opposite surfaces; this process is known as Spin-Hall Effect (SHE). When a ferromagnet is generated on such a metal, those accumulated spins diffuse into the magnet and can switch its magnetization, which has applications in magnetic memory devices. To detect the spin accumulations directly on the heavy metal surface without a ferromagnet, we use a technique known as magnetization-induced second harmonic generation (MSHG). From this technique, we expect to observe the contrast in spin orientation or Asymmetry at the surfaces of the sample. The Asymmetry is a proportional representation of magnetic moment of the accumulated spins at the surfaces and interfaces of the metal. Such a direct observation enables us to unearth the physics of spin accumulation, such as the spin life-time and spin diffusion length.
Project Poster: Link
Undergraduate Researcher: Maurice Roots
Major: Physics
Home Institution: Hampton University
Research Project: Effects of Supply Voltage and Body Bias on Variability of NEM Relay Switching Voltage
HBCU Faculty Advisor: Dr. Michelle Claville
UCB Faculty Advisor: Dr. Tsu-Jae King Liu
Mentor: Benjamin Osoba
Abstract: The Nano-Electro-Mechanical (NEM) relay is a promising switch design for ultra-low-power digital computation because it can achieve negligible off-state leakage current (to eliminate static power dissipation) and transition abruptly between ON and OFF states (to enable sub-100 mV operation). Variability in relay switching voltages can limit reductions in operating voltage, however, and therefore should be systematically quantified. In this work, the effects of the supply voltage (VDD) and the body bias voltage (VB) on variability in relay pull-in voltage (VPI) and release voltage (VRL) are investigated.
Project Poster: Link
Undergraduate Researcher: Aman Williams
Major: Mechanical Engineering Technology
Home Institution: Virginia State University
Research Project: Spin-Coating Perovskite Solar Cells on Plastic
HBCU Faculty Advisor: Dr. Peng Cheng
UCB Faculty Advisor: Dr. Vivek Subramanian
Mentor: Matt McPhail
Abstract: Perovskite solar cells (PSCs) have received great attention in the photovoltaics community due to multiple recent breakthroughs. The goal of this research is to develop a spin-coating process of each PSC layer onto a plastic substrate instead of on the widely used glass substrate. The
current method of spin-coating on plastic is the same used for glass. However, multiple issues arise when spinning on plastic due to its material properties, such as non- uniformities found around the substrates’ edges, warping of the substrate during annealing, and the uniformity of the electron and hole interface layers. In order to solve these issues an etching process, a Teflon holder, and a slower spin speed for the electron interface layer were added to the original spin-coating process for plastic substrates. To assess the efficacy of this process, several optical and electrical measurements were performed via Olympus profilometer, atomic force microscope, and solar simulator.
Project Poster: Link
Undergraduate Researcher: Chidubem Dimukeje
Major: Electrical Engineering
Home Institution: University of Maryland Eastern Shore
Research Project: Investigating Effects of Non-idealities in Thermophotovoltacis System Performance
HBCU Faculty Advisor: Dr. Lei Zhang
UCB Faculty Advisor: Prof. Eli Yablonovitch
Mentor: Zunaid Omair
Abstract: Thermophotovoltaics (TPVs) are heat engines that convert thermal radiation from a local hot body to electricity. A basic thermophotovoltaics system consists of a thermal emitter and a photovoltaic cell. In an effort to achieve a high thermophotovoltaic efficiency with a 0.74eV band gap InGaAs cell and a 96% high-reflectivity back mirror using a 1200ᵒC thermal emitter in a vacuum chamber, we must understand the effect of non-idealities in thermophotovoltaic system conversion, and perform Calorimetry experiments to determine the source of leakage in the thermophotovoltaic chamber and calibrate future experiments with the photovoltaic cell.
Project Poster: Link