MEMS Hybrid Electronic Integration: From Micro-Robotic Actuation to Control and Monitoring of MEMS Sensor

This work presents two hardware implementations for controlling MicroElectroMechanical Systems (MEMS) in mechatronic systems across different scales. The first project focuses on advancing micro-robotic swarm control through improvements to Field Programmable (FP) MicroStressBots. These micro-robots rely on electrostatic actuation and utilize Untethered Scratch Drive Actuation (USDA) for translational motion. Individual selectivity and rotational control are achieved through an electrostatically actuated steering arm, which is programmed via stress-engineering of the arm. While several theoretical control strategies for micro-robotic swarms have been proposed, they often neglect the non-idealities associated with programming constraints. Although the command complexity remains O(c), in practice, only a finite number of micro-robots can be operated simultaneously without address conflicts. To address this limitation, this work introduces an expanded steering arm design incorporating MEMS relay logic to electrically isolate the steering arm. The addition of Normally Open (NO) and Normally Closed (NC) cantilevers enables power delivery only when a valid addressing sequence is provided. Programming of these relay logic cells is achieved through a new stress-engineering method using localized shadow masks fabricated by two-photon polymerization (2PP) micro-scale 3D printing. These 3D-printed masks feature geometries designed for simple release and precise placement over the MEMS relay logic cells. This development represents a significant step toward practical micro-robotic swarm control. In parallel, two exploratory studies were conducted to enhance electrostatic micro-robotic systems. The first investigated the use of high-permittivity (high-k) dielectrics to strengthen electrode fields and potentially reduce operating voltages for FP MicroStressBots. The second explored the fabrication of electrostatic devices by sputter-coating 2PP 3D-printed structures with metal. The second project addresses the need for monitoring respirable particulate matter (PM) smaller than 4 μm, which can remain suspended in air for extended periods and is prevalent in environments such as coal mines and diesel exhaust. These particles are linked to respiratory illnesses, including Coal Workers’ Pneumoconiosis (CWP), lung cancer, and silicosis, with disease severity inversely correlated with particle size. This work builds upon the Wearable Respirable Dust Monitor (WEARDM), a dual MEMS gravimetric sensor platform for high-sensitivity PM detection. The original WEARDM used a Quartz Crystal Microbalance (QCM) to detect particles between 4 μm and 1.3 μm, and a Film Bulk Acoustic Resonator (FBAR) for particles below 1.3 μm. These sensors were previously characterized using benchtop equipment to determine sensitivity and saturation limits. To advance toward a wearable, self-contained solution, this work integrates the system onto a single printed circuit board (PCB) containing a microcontroller, a radio-frequency (RF) conditioning circuit, and a five-output power supply to power and monitor the sensors. This marks the next logical step toward a fully wearable respirable dust monitoring device.