Opposition is a unique function attributed to the shape and position of the thumb, and is an essential component of hand function that thumb prostheses must be able to perform. When designing a prosthetic device, it's important that the appearance of the prosthetic thumb, including shape and texture, mimic a biological thumb to help support function and to allow for the user to perceive the device as part of the body. This process, called embodiment, is supported by creating anthropomorphic, or human-like devices. This research project is built off of the development of a fully-implantable thumb prosthesis that will be covered by the patient’s skin in order to help restore the ability for the patient to sense texture and temperature, allowing for embodiment. The goal of this research project was to test different thumb tip shapes for the fully-implantable thumb prosthesis to see which shape is the most anthropomorphic. AutoCad was used in order to create and model various thumb tip shapes based on radiographic data of the thumb, then the parts were 3D printed. Next, cadaver forearm skin was placed on top of the parts to assess how the parts looked underneath human skin, and to see which looked the most anthropomorphic. There were a total of eight thumb tips printed and used in the cadaver forearm dissection.

Information transmitted over a noisy channel can be corrupted by noise that can flip or erase bits. One technique to recover the original signal is to send an encoded message that carries redundant bits of information, known as parity bits. Low Density Parity Check (LDPC) codes are widely used for encoding messages. Their key feature is a parity-check matrix with a low density of ones, which allows for efficient decoding by requiring a small number of computations per parity check equation. There are several algorithms available to decode LDPC codes via iterative message passing to estimate the message bits. Min-Sum is one such algorithm, which approximates the theoretical node computations by simple minimum and addition operations. The Min-Star algorithm reduces frame error rate (FER) with minimal additional complexity by adding a correction factor to the determination of the minimum. In this research, we investigate the accuracy of Min-Star compared to Min-Sum for different code rates, a ratio that determines the amount of redundancy added to a message. Our results show that Min-Star results in lower FER than Min-Sum when the algorithms are limited to 100 iterations. Furthermore, we adapt an FPGA implementation of Min-Star to work with the different code rates that match the performance standards set by the Consultative Committee For Space Data Systems (CCSDS). Similarly, we generate FER plots for different Code Rates and plot them against the CCSDS performance curves. We find that our implementation performs in alignment with the standard.

Mobile cellular phones, among many modern devices, require the use of multiple-in multiple-out (MIMO) receiver technology in order to communicate globally. These device’s integrated receivers utilize off-chip Surface Acoustic Wave (SAW) filter technology to eliminate undesired signals. However, these filters take up expensive board real estate. Despite their high selectivity, SAW filters have fixed center frequencies and are unable to exceed frequencies above 3 GHz. By leveraging the filtering by aliasing technique, the SAW filter can be replaced by a highly linear adjustable bandpass filter that yields comparable outcomes in filtering interfering out-of-band signals (blockers) over 0.2 to 5 GHz enabling high dynamic range reception. This SAW-less front-end technology can aid in the future miniaturization of receiver design. A radio frequency integrated circuit (RFIC) containing this new filter necessitates a robust testing circuit capable of emulating four simultaneous RF signals and blockers targeting the receiver inputs. A PCB was engineered in Altium Designer to drive and interface with the RFIC. The completed design included four 50 Ohm RF inputs, a differential local oscillator input, and a 10 GHz digital clock input. It was simulated within Keysight ADS in order to validate the driver’s transmission lines’ proficiency in minimizing reflections across a broad band, thus ensuring good signal integrity. Future work requires the design of an RF attenuator-based PCB capable of beamforming akin to that of a MIMO transmitter and the development of a python control program capable of testing the RFIC.

Soft robotics is an innovative field at the intersection of engineering and biology, focusing on the development of robots composed of flexible materials. Unlike traditional rigid robots, soft robots mimic the adaptability and versatility of natural organisms, enabling them to interact uniquely in dynamic environments. Providing electrical energy to these robots typically demanded rigid elements like batteries or solar panels. Hence, a novel approach is needed to construct a fully self-powered soft robot. Recent literature has demonstrated the applications of a composite with a liquid crystal elastomer (LCE) and silicone rubber PDMS (polydimethylsiloxane). The LCE, doped with a light-absorbing agent will shrink in response to light, causing constant undulations when illuminated. The conversion of these undulations to electrical energy can be accomplished using the triboelectric effect, where the contact-separation of PDMS and the nonstick material PTFE (polytetrafluoroethylene) build up electric charges on the surface of the materials to be measured as voltage. The experimental device was created by adhering with silicone glue the strips of material in the following order: LCE-PDMS-PTFE-LCE. Under illumination with a 780mW/cm$^2$ laser, undulations in the device arose, and an AC voltage of amplitude up to 50 mV and frequency up to 1 Hz was generated. These undulations mirrored those of stingrays, suggesting a new bio-inspired pathway for energy harvesting. Overall, we conclude that a multilayered design combining the LCE oscillator and the triboelectric properties of PTFE is a viable way of providing power to the autonomous soft robots of the future.