Shape‐Controlled Flexible Microelectronics Facilitated by Integrated Sensors and Conductive Polymer Actuators

Abstract

Flexible electronics has gained tremendous attention over the past decades, revolutionizing fields such as telecommunication, multimedia, and healthcare. [1] Major electronic components, e.g., interconnects, antennas, diodes, and transistors, have been fabricated on thin polymeric foils to generate new options in the toolkit of developers. Applying thin polymeric foils as substrates facilitates the production of electronic systems with low weight, shape compliance, robustness, and reliability with ever-increasing complexity. The ultrathin design of these electronic devices has promoted bioelectronics that include artificial skins, [2] sensor arrays, [3] electronic implants such as brain probes, [4] and nerve cuffs, [5] to name a few. The ability to naturally conform to complex 3D shaped anatomies is a vital feature for electronic devices to interact with soft biological tissue. And while the shape of a large-area flexible electronic device can be easily adapted manually to the geometric requirements of the final application, handling becomes increasingly more challenging when aiming at smaller dimensions, when, e.g., a submillimeter nerve fiber bundle has to be enclosed gently with a similarly small cuff implant. [6] Shapeable microelectronic devices, which transform their shape on demand, provide an alternative strategy to accomplish this challenging task. [7] For instance, soft microscale structures with integrated electronic circuits have recently been demonstrated to wrap around peripheral nerves in situ when exposed to elevated temperatures or moisture. [8,9] These devices, however, lack the ability to reshape repeatedly and on demand in the operating environment. Such functionalities require the integration of biocompatible flexible shape and position sensors together with robust microactuators, fabricated ideally by a monolithic wafer-scale process.Among a variety of small-scale actuators that are driven by pneumatic [10,11] and hydraulic [12] pressure, electric [13] and

Digital Electrochemistry for On‐Chip Heterogeneous Material Integration

“…PPy was used as a model material to demonstrate the concept of digital electrochemistry, since it is a well‐known conducting polymer widely used in electrochemical sensors and actuators. [ 29–31 ] Figure a shows a two‐electrode electrochemical reaction cell, where the a‐IGZO TFT active‐matrix is used as the working electrode (WE), and Ag/AgCl is used as a counter electrode (CE). We used pyrrole monomer aqueous solution as the electrolyte containing 0.1 m pyrrole and 0.1 m sodium dodecylbenzenesulfonate (NaDBS).…”

“…[ 10 ] Recently, our group has reported a PPy‐based intelligent actuator system with position and strain feedback control. [ 31 ] Here, a‐IGZO TFT active‐matrix‐driven PPy actuator arrays were fabricated to demonstrate the capability of the digital electrochemistry approach in electrochemical actuator integration. To construct actuator pixels, the metal reaction pads were replaced by SU‐8 passivated Au stripes.…”

Electronically integrated microcatheters based on self-assembling polymer films

“…Substrates carrying eight ISACS (image in fig. S1) were diced; devices were electrically connected, and the manipulator digits were electrochemically coated with the conductive polymer polypyrrole (PPy) ( 44 , 45 ). Then, the SL was selectively removed in a wet chemical process to initiate the catheter self-assembly into a rolled-up tube ( Fig.…”

“…Opening the manipulator requires about 5 s with a bias scan speed of 100 mV s −1 , and it takes another 6 s to fully close the manipulator. Note that this time is defined by the scan speed and actuator stacks of PI/Au/PPy were shown to fully reshape in less than a second ( 44 ). On the basis of previous reports on closely related actuated devices ( 44 , 51 ), the actuator force of ISAC manipulators can be estimated to be about 1 mN per actuator (details in Materials and Methods).…”

A High Spatiotemporal Resolution Ultrasonic Ranging Technique With Multiplexing Capability

“…igh performance ranging techniques operating in intermediate (10 -2 -10 1 m) full-scale range (FSR) are essential for next generation human machine interfaces [1]- [3], IoT services [4], navigation of autonomous systems [5], [6] and medical tools [7] to name a few. Among them there are modern application scenarios such as tracking of micro-robots [8], [9] or minimally invasive medical catheters [10] and endoscopes [11], [12]. Ranging systems for these applications need to be capable of providing positions of multiple objects moving at Submitted on 2021.07.21.…”