Connect with us

Tech

Reinventing fiber-based pressure sensors with a unique internal structure

Published

on

Reinventing fiber-based pressure sensors with a unique internal structure


TGTMW fibers display a unique increase in resistance in response to pressure changes, which makes these innovative fibers a promising candidate for application as flexible pressure sensors in a wide variety of fields, including gesture-based control, robotic grippers, smart textiles, and medical care. Credit: Dr. Chunhong Zhu from Shinshu University, Japan

Pressure sensors are crucial in many emerging applications, but traditional designs are often bulky or inflexible. In a recent study, researchers from Japan developed a fiber-shaped pressure sensor that overcomes this limitation by increasing—rather than decreasing—its resistance when compressed. Owing to a unique multi-walled conductive core made from graphene nanoplatelets, these fibers could enable fine-tuned tactile sensing for next-generation smart textiles and robotic grippers.

The need for pressure sensors has been steadily increasing across diverse applications, from robotic grippers that need accurate tactile feedback to wearable devices that monitor . Ideally, to be effectively integrated into prosthetic limbs, smart textiles, or robots, pressure sensors need to be flexible, sensitive, and durable. However, traditional film-based and aerogel-based sensors are often too large and rigid, hindering their adoption in many fields.

These limitations have motivated research into fiber-based pressure sensors, which could offer enhanced versatility and miniaturization. A major hurdle that remains is the design of a sensing mechanism that works efficiently given a fiber’s series circuit structure.

In a conductive fiber, a local decrease in resistance, which is the common response for most pressure sensors, has a small impact on the fiber’s overall conductivity. To be truly effective, a fiber pressure sensor needs to exhibit the opposite behavior: a substantial increase in overall resistance when compressed.

Now, a research team including Dr. Ziwei Chen, from Shinshu University, Japan, and led by Associate Professor Chunhong Zhu also from Shinshu University, Japan, has overcome this challenge through an innovative approach to fiber design. Their study was published online in the journal Advanced Materials on July 16, 2025. The researchers developed a unique multi-walled fiber exhibiting a unique mechanism that modulates resistivity under pressure, addressing a fundamental problem in fiber-based pressure sensors.

The new were prepared via a coaxial wet-spinning process, producing a smooth outer shell of thermoplastic polyurethane (TPU) and titanium dioxide (TiO₂) and a core containing 2D graphene nanoplatelets (GNPs). By leveraging the van der Waals interactions and self-stacking behavior of these flat GNPs, the fiber core adopted a multi-wall structure that was critical to their function. Thus, the team named their creation TGTMW fibers (TiO₂/graphene/thermoplastic polyurethane multi-wall fibers).

Through extensive structural analysis and experimentation, the researchers showed that when a portion of a TGTMW fiber is compressed, the internal multi-wall structure bends and develops microcracks. These microcracks disrupt the conductive pathways of the axially aligned GNPs, causing a sharp increase in the fiber’s electrical resistance. This mechanism allows the TGTMW fiber to produce a highly responsive signal even when only a small section is compressed. To put this into perspective, a sensor using a TGTMW fiber is sensitive enough to detect a light fingertip touch with a minimum pressure of only 0.1 N.

Notably, the high aspect ratio of the TGTMW fibers makes them ideal for applications that require fine-grained tactile feedback. For instance, in soft robotics, these fibers could be integrated into the fingertips of robotic grippers used for elderly care or medical assistance.

“Most available tactile sensors used on robotic hands are rigid, which poses the risk of causing discomfort or even injury during contact with humans. In contrast, fiber-shaped flexible offer both comfort and compliance, reducing the risk of harm,” remarks Dr. Zhu.

Furthermore, TGTMW fibers can be used to distinguish between different types of tactile events. The researchers showed that by using wavelet transforms on data from a three-fiber array, they could accurately differentiate between various forms of presses and slides.

“This capability is particularly valuable for the tactile sensing of frictional states, enabling to distinguish between static and dynamic friction—much like human fingertips do—potentially allowing robotic manipulation to become as nuanced and dexterous as that of humans,” highlights Dr. Zhu.

The scalability of the TGTMW fibers also opens the door to novel designs in smart textiles and interactive surfaces. Systems capable of gesture detection could be embedded into specialized garments for human-machine interaction in challenging environments where touchscreens are impractical, such as underwater or in space.

Looking ahead, the researchers believe this work represents a foundational shift in tactile sensors. “To put it boldly, our work could be seen as the beginning of a new subfield—introducing a distinct fiber-based pressure sensor architecture and offering a working prototype with solid performance,” concludes Zhu. “The proposed TGTMW fiber, with its innovative design, distinct structure, and versatile applications, holds immense potential for advancing flexible sensors and next-generation smart devices.”

More information:
Ziwei Chen et al, Fibrous Pressure Sensor with Unique Resistance Increase under Partial Compression: Coaxial Wet‐Spun TiO2/Graphene/Thermoplastic Polyurethane Multi‐Wall Multifunctional Fiber, Advanced Materials (2025). DOI: 10.1002/adma.202509631

Provided by
Shinshu University


Citation:
Reinventing fiber-based pressure sensors with a unique internal structure (2025, August 27)
retrieved 27 August 2025
from https://techxplore.com/news/2025-08-reinventing-fiber-based-pressure-sensors.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.





Source link

Tech

I’ve Tried Every Digital Notebook. Here Are the Best Ones on Sale

Published

on

I’ve Tried Every Digital Notebook. Here Are the Best Ones on Sale


I love a digital notebook. I write about them all year long here at WIRED, and it’s not often my favorites go on sale. (Or for any to go on sale, besides Amazon’s own sale events.) But this year, multiple digital notebooks I love are on sale for the biggest sale event of the year.

If you’ve thought about getting one of these for yourself, there’s truly no better moment. From reMarkable’s on-sale bundles to Kobo’s deals, you can shop five of the best digital notebooks we’ve ever tried right now at a lower price than you might find until next year. They’re a handy device just about everyone can enjoy, whether you want to digitally annotate your books or write out your grocery list without using a piece of paper.

Looking for more great sales to shop? Don’t miss our guides to the Best Amazon Device and Kindle Deals, Best Laptop Deals, the Absolute Best Cyber Monday Deals, and our liveblog.

Update Dec. 1: We updated prices, links, and deals, and added the Rocketbook Fusion Plus notebook.

The Best Digital Notebook Deals

  • Photograph: Nena Farrell

Some of the best digital notebooks we’ve tried come from reMarkable, and one of reMarkable’s models always seems to reign supreme over our digital notebooks guide. While the Paper Pro Move is the newest model, the reMarkable Paper Pro that launched in September 2024 is my current all-around favorite. It’s not only powerful with tons of tools and an easy interface, but packs a color screen for colorful notes. It also has a gentle front light so that you can use it in darker environments. You can get the bundles on sale right now, so combine one of reMarkable’s markers and folio covers with a Paper Pro to get $50 off.

  • Photograph: Nena Farrell

The best discount from reMarkable is actually for its older device and our previous top pick, the reMarkable 2. It doesn’t have a color screen or the front light, but you’ll get the reMarkable’s great software and options for accessories like the Keyboard Folio to use it like a laptop. The reMarkable 2 bundles are also on sale, so add on your favorite folio of choice on reMarkable’s website to get $70 off.

  • Photograph: Nena Farrell

  • Courtesy of Kobo

The Kobo Libra Colour is my favorite all-around e-reader with its color screen and page turner buttons, but you can add on a stylus to have it double as a digital notebook. It’s one of the more affordable options, and it’s a smaller screen than the rest of these, but I especially love that you can use the stylus to doodle on the books you’re reading (something you can’t do with the Kindle Scribe). It’s $30 off on Kobo’s site for Cyber Monday.

  • Photograph: Nena Farrell

  • Photograph: Nena Farrell

  • Courtesy of Amazon

Amazon

Kindle Scribe (2024)

The second-generation Kindle Scribe isn’t the best digital notebook, but the long battery life (12 weeks!!) and convenient starting point of it being a Kindle I could already be reading on makes it a great go-to for casual notetakers and doodlers. It’s a good choice for Kindle and Amazon users, and there are new models due out this winter, but they likely won’t be as cheap as this one. (Especially since some of those new models will have color!)

Kobo Elipsa 2E, a digital notebook with a smart pen (stylus) on top of a wrinkled white sheet with the screen showing a page from an e-book and handwritten notes scribbled in the margins

Photograph: Nena Farrell

If you like the idea of getting a Kobo e-reader that doubles as a digital notebook, you can go for more of a classic size with the larger Elipsa 2E. This one comes with the stylus, so you won’t have to add it on, and it’s $50 off.

Black digital notebook with a black pen on white surface

Photograph: Nena Farrell

The Rocketbook Fusion Plus digital planner and notebook is for those who don’t want to charge their notebook or give up on the whole “paper” experience. Take notes with the included, erasable Pilot Frixion Pen, scan photos of the pages into the app, and erase the whole thing with the damp microfiber cloth (also included). Fusion Plus is on its steepest discount of recent memory, and comes templates that range from monthly and weekly pages to project management and meeting notes.


Power up with unlimited access to WIRED. Get best-in-class reporting and exclusive subscriber content that’s too important to ignore. Subscribe Today.



Source link

Continue Reading

Tech

Artificial tendons give muscle-powered robots a boost

Published

on

Artificial tendons give muscle-powered robots a boost



Our muscles are nature’s actuators. The sinewy tissue is what generates the forces that make our bodies move. In recent years, engineers have used real muscle tissue to actuate “biohybrid robots” made from both living tissue and synthetic parts. By pairing lab-grown muscles with synthetic skeletons, researchers are engineering a menagerie of muscle-powered crawlers, walkers, swimmers, and grippers.

But for the most part, these designs are limited in the amount of motion and power they can produce. Now, MIT engineers are aiming to give bio-bots a power lift with artificial tendons.

In a study appearing today in the journal Advanced Sciencethe researchers developed artificial tendons made from tough and flexible hydrogel. They attached the rubber band-like tendons to either end of a small piece of lab-grown muscle, forming a “muscle-tendon unit.” Then they connected the ends of each artificial tendon to the fingers of a robotic gripper.

When they stimulated the central muscle to contract, the tendons pulled the gripper’s fingers together. The robot pinched its fingers together three times faster, and with 30 times greater force, compared with the same design without the connecting tendons.

The researchers envision the new muscle-tendon unit can be fit to a wide range of biohybrid robot designs, much like a universal engineering element.

“We are introducing artificial tendons as interchangeable connectors between muscle actuators and robotic skeletons,” says lead author Ritu Raman, an assistant professor of mechanical engineering (MechE) at MIT. “Such modularity could make it easier to design a wide range of robotic applications, from microscale surgical tools to adaptive, autonomous exploratory machines.”

The study’s MIT co-authors include graduate students Nicolas Castro, Maheera Bawa, Bastien Aymon, Sonika Kohli, and Angel Bu; undergraduate Annika Marschner; postdoc Ronald Heisser; alumni Sarah J. Wu ’19, SM ’21, PhD ’24 and Laura Rosado ’22, SM ’25; and MechE professors Martin Culpepper and Xuanhe Zhao.

Muscle’s gains

Raman and her colleagues at MIT are at the forefront of biohybrid robotics, a relatively new field that has emerged in the last decade. They focus on combining synthetic, structural robotic parts with living muscle tissue as natural actuators.

“Most actuators that engineers typically work with are really hard to make small,” Raman says. “Past a certain size, the basic physics doesn’t work. The nice thing about muscle is, each cell is an independent actuator that generates force and produces motion. So you could, in principle, make robots that are really small.”

Muscle actuators also come with other advantages, which Raman’s team has already demonstrated: The tissue can grow stronger as it works out, and can naturally heal when injured. For these reasons, Raman and others envision that muscly droids could one day be sent out to explore environments that are too remote or dangerous for humans. Such muscle-bound bots could build up their strength for unforeseen traverses or heal themselves when help is unavailable. Biohybrid bots could also serve as small, surgical assistants that perform delicate, microscale procedures inside the body.

All these future scenarios are motivating Raman and others to find ways to pair living muscles with synthetic skeletons. Designs to date have involved growing a band of muscle and attaching either end to a synthetic skeleton, similar to looping a rubber band around two posts. When the muscle is stimulated to contract, it can pull the parts of a skeleton together to generate a desired motion.

But Raman says this method produces a lot of wasted muscle that is used to attach the tissue to the skeleton rather than to make it move. And that connection isn’t always secure. Muscle is quite soft compared with skeletal structures, and the difference can cause muscle to tear or detach. What’s more, it is often only the contractions in the central part of the muscle that end up doing any work — an amount that’s relatively small and generates little force.

“We thought, how do we stop wasting muscle material, make it more modular so it can attach to anything, and make it work more efficiently?” Raman says. “The solution the body has come up with is to have tendons that are halfway in stiffness between muscle and bone, that allow you to bridge this mechanical mismatch between soft muscle and rigid skeleton. They’re like thin cables that wrap around joints efficiently.”

“Smartly connected”

In their new work, Raman and her colleagues designed artificial tendons to connect natural muscle tissue with a synthetic gripper skeleton. Their material of choice was hydrogel — a squishy yet sturdy polymer-based gel. Raman obtained hydrogel samples from her colleague and co-author Xuanhe Zhao, who has pioneered the development of hydrogels at MIT. Zhao’s group has derived recipes for hydrogels of varying toughness and stretch that can stick to many surfaces, including synthetic and biological materials.

To figure out how tough and stretchy artificial tendons should be in order to work in their gripper design, Raman’s team first modeled the design as a simple system of three types of springs, each representing the central muscle, the two connecting tendons, and the gripper skeleton. They assigned a certain stiffness to the muscle and skeleton, which were previously known, and used this to calculate the stiffness of the connecting tendons that would be required in order to move the gripper by a desired amount.

From this modeling, the team derived a recipe for hydrogel of a certain stiffness. Once the gel was made, the researchers carefully etched the gel into thin cables to form artificial tendons. They attached two tendons to either end of a small sample of muscle tissue, which they grew using lab-standard techniques. They then wrapped each tendon around a small post at the end of each finger of the robotic gripper — a skeleton design that was developed by MechE professor Martin Culpepper, an expert in designing and building precision machines.

When the team stimulated the muscle to contract, the tendons in turn pulled on the gripper to pinch its fingers together. Over multiple experiments, the researchers found that the muscle-tendon gripper worked three times faster and produced 30 times more force compared to when the gripper is actuated just with a band of muscle tissue (and without any artificial tendons). The new tendon-based design also was able to keep up this performance over 7,000 cycles, or muscle contractions.

Overall, Raman saw that the addition of artificial tendons increased the robot’s power-to-weight ratio by 11 times, meaning that the system required far less muscle to do just as much work.

“You just need a small piece of actuator that’s smartly connected to the skeleton,” Raman says. “Normally, if a muscle is really soft and attached to something with high resistance, it will just tear itself before moving anything. But if you attach it to something like a tendon that can resist tearing, it can really transmit its force through the tendon, and it can move a skeleton that it wouldn’t have been able to move otherwise.”

The team’s new muscle-tendon design successfully merges biology with robotics, says biomedical engineer Simone Schürle-Finke, associate professor of health sciences and technology at ETH Zürich.

“The tough-hydrogel tendons create a more physiological muscle–tendon–bone architecture, which greatly improves force transmission, durability, and modularity,” says Schürle-Finke, who was not involved with the study. “This moves the field toward biohybrid systems that can operate repeatably and eventually function outside the lab.”

With the new artificial tendons in place, Raman’s group is moving forward to develop other elements, such as skin-like protective casings, to enable muscle-powered robots in practical, real-world settings.

This research was supported, in part, by the U.S. Department of Defense Army Research Office, the MIT Research Support Committee, and the National Science Foundation.



Source link

Continue Reading

Tech

The Best Cyber Monday Streaming Deals With a Convenient Roommate’s Email Address

Published

on

The Best Cyber Monday Streaming Deals With a Convenient Roommate’s Email Address


HBO knows you’re bored and cold. It wants you to Max and chill with Noah Wyle in scrubs. The company offers some of the best Cyber Monday streaming deals with a ridiculously low-priced $3/month offer for basic HBO Max (it’s the version with ads and 2K streaming, but still, super-cheap). Disney Plus and Hulu deals are bundled up for $5/month. Apple TV wants back in your life for $6.

Of course, this deal is only meant for new customers. Not boring ol’ existing customers. If you already have basic HBO Max, you’re already paying $11 for the same service, and HBO would like you to keep doing that. Streaming apps are banking on you being complacent and happy in your streaming life. Maybe they’re even taking you for granted.

Sometimes you can get the current deal just by threatening to cancel, or actually canceling, your account. Suddenly, you’re an exciting new customer again! Another method is by using an alternate email account (perhaps your spouse’s or roommate’s?) and alternate payment information as a new customer. If you do use a burner email (you did not hear this from me), check in on your favorite app’s terms of service to make sure you’re not in violation by re-enrolling with different emails. I’ll also issue the caveat that you lose all your viewing data and tailored suggestions if you sign up anew.

But times and wallets are tight! And $3 HBO Max sounds pretty good. After all, every middle-aged American man needs to rewatch The Wire once every five years or so—assuming he’s not the kind of middle-aged man who rewatches The Sopranos instead. Here are the current best streaming deals for Cyber Monday 2025.


Devon Maloney; ARCHIVE ID: 546772

Regular price: $80



Source link

Continue Reading

Trending