Recent Advances in Micro-Electro-Mechanical Devices for Controlled Drug Release Applications

Abstract

In recent years, controlled release of drugs has posed numerous challenges with the aim of optimizing parameters such as the release of the suitable quantity of drugs in the right site at the right time with the least invasiveness and the greatest possible automation. Some of the factors that challenge conventional drug release include longterm treatments, narrow therapeutic windows, complex dosing schedules, combined therapies, individual dosing regimens, and labile active substance administration. In this sense, the emergence of micro-devices that combine mechanical and electrical components, so called micro-electro-mechanical systems (MEMS) can offer solutions to these drawbacks. These devices can be fabricated using biocompatible materials, with great uniformity and reproducibility, similar to integrated circuits. They can be aseptically manufactured and hermetically sealed, while having mobile components that enable physical or analytical functions together with electrical components. In this review we present recent advances in the generation of MEMS drug delivery devices, in which various micro and nanometric structures such as contacts, connections, channels, reservoirs, pumps, valves, needles, and/or membranes can be included in their design and manufacture. Implantable single and multiple reservoir-based and transdermalbased MEMS devices are discussed in terms of fundamental mechanisms, fabrication, performance, and drug release applications.

Memristor Circuits for Colloidal Robotics: Temporal Access to Memory, Sensing, and Actuation

“…Using the GRI as a model engineering application, we instead dock the memristor array circuit with an electric actuation mechanism found in immobile implantable chips. Such an actuation scheme allows for scheduled dosing of multiple medications, [ 106–108 ] and the clean‐cut electric switching enables controlled and pulsatile delivery. [ 106,109 ] Our architecture is illustrated in Figure A, where a drug‐loaded electric actuation module accesses a memristor array's time‐indexed data and delivers cargo accordingly.…”

Fast Electrochemical Actuator with Ti Electrodes in the Current Stabilization Regime

“…Microfluidic systems are widely used in biology, chemistry, and medicine for cell culturing and manipulation [1,2], synthesis of materials [3,4], pathogen detection [5,6], and other purposes. One of the recent advances in microfluidics is implantable drug delivery modules, which provide controlled release of the drug directly to the target organ or tissue, bypassing the physiological barriers of the body [7][8][9][10]. These modules require a built-in pump that pushes the liquid through the microneedle.…”

A Peristaltic Micropump Based on the Fast Electrochemical Actuator: Design, Fabrication, and Preliminary Testing

“…The performance of the device is mainly determined by the pump. Several working principles are used for micropump as described in recent reviews [14,15]. Osmotic pumps [16][17][18] are compact, easy to fabricate, and do not require external energy source, but provide a small and unregulated flow rate.…”