This paper investigates how the electromechanical response of MEMS/NEMS devices changes when the geometrical characteristics of their embedded flexural hinges are modified. The research is dedicated particularly to MEMS/NEMS devices which are actuated by means of rotary comb-drives. The electromechanical behavior of a chosen rotary device is assessed by studying the rotation of the end effector, the motion of the comb-drive mobile fingers, the actuator’s maximum operating voltage, and the stress sustained by the flexure when the flexure’s shape, length, and width change. The results are compared with the behavior of a standard revolute joint. Outcomes demonstrate that a linear flexible beam cannot perfectly replace the revolute joint as it induces a translation that strongly facilitates the pull-in phenomenon and significantly increases the risk of ruptures of the comb-drives. On the other hand, results show how curved beams provide a motion that better resembles the revolute motion, preserving the structural integrity of the device and avoiding the pull-in phenomenon. Finally, results also show that the end effector motion approaches most precisely the revolute motion when a fine tuning of the beam’s length and width is performed.

This work presents a MEMS microgripping device integrated with cooperating actuators in a pseudoparallel configuration, as a novel method to address modern micro- and nanomanipulation applications. Pseudoparallel rotary comb drives, arranged in a newly conceived floating-centered layout, are proposed as a route to multifunctional, multioperation micromanipulators. The concept is demonstrated through a modular multilink device, in which functional units such as actuators and sensors can be added or removed without altering the main structural layout. The design is also easily scalable, as it exploits electrostatic actuation, more efficient at small scales, and is compatible with standard silicon-on-insulator MEMS processes. To validate the concept, a prototype was fabricated and tested across multiple scenarios, accompanied by numerical simulations on a digital twin. Results highlight improved actuation and sensing capabilities compared to previous architectures. Pseudoparallel modules increased tip motion up to 14.4% and force exertion up to 30.5% relative to the non-parallel configurations without altering the four-bar kinematics, while adding actuation functionalities and enabling simultaneous motion and force feedback, with achieved sensitivities of 6.26 fF/$\upmu$m and 12.44 fF/$\upmu$N, respectively. The system demonstrates compactness, versatility, and modularity, making it promising for applications in micro/nanosurgery, biological manipulation, and robotic microassembly.

The growing demand for wearable and Internet of Medical Things (IoMT) devices is driving the development of compact, low-power platforms for continuous physiological monitoring. Bioimpedance analysis represents a versatile non-invasive technique for the assessment of tissue properties, body composition, and respiratory dynamics. This work presents a comprehensive experimental validation of a compact bioimpedance measurement platform based on the SENSIPLUS chip, a CMOS sensor interface integrating a frequency-programmable lock-in amplifier for Electrochemical Impedance Spectroscopy in the 10 kHz–1 MHz range. The platform was validated at three complementary levels: (i) electrical characterization on Debye tissue-equivalent circuits using a three-point bilinear calibration, with analysis of the electrode–skin contribution and repeatability assessment; (ii) in vivo multi-frequency bioimpedance spectroscopy (BIS) with Cole–Cole model fitting and hook-effect correction; and (iii) single-frequency thoracic impedance plethysmography for respiratory monitoring. Results were compared against an Agilent E4980A precision Inductance (L), Capacitance (C), and Resistance (R) meter and a calibrated spirometer. The presented device achieved a maximum resistance error below 5.7% and reactance deviation under 6 $\mathsf{\Omega }$ across the investigated frequency range, Cole–Cole parameters consistent with reference values, and strong linear correlation ($R^2=0.97$) between thoracic impedance variations and tidal volume, with respiratory rate estimation errors below 2% across the ten sessions, specifically 1.43% during normal breathing and 1.96% during deep breathing. These results demonstrate that the SENSIPLUS-based platform achieves metrological performance compatible with the requirements of wearable IoMT applications, here demonstrated in a single-subject proof-of-concept study, while relying for all critical analog functions on a compact ($1.5\times 1.5$) mm² system-on-chip with low power consumption (1.5 mW).