editor's blog
Subscribe Now

MEMS Caps that Push Both Ways

The many bands that cellphones must support, coupled with environmental changes that can have a dramatic effect on the effectiveness of a phone’s antenna, have made the concept of antenna “tuning” particularly relevant. We looked at WiSpry’s approach to this some time ago. The concept involves an array of capacitors that can be reconfigured in real time to change the characteristics of the antenna and improve reception.

Most such MEMS capacitor arrays consist of cantilevers – like diving boards – or bridges – basically, cantilevers supported on both ends. (Which… makes them not cantilevers… yes, I understand…) But there’s a new company, just on the heels of a funding round, that has proposed a different way to build the capacitor.

DelfMEMS (I was so expecting them to be associated with Delft, the Netherlands, but no… they’re French) points to stiction as a particular problem for these traditional structures. Stiction is the tendency of a variety of influences – atomic forces, residual gunks, etc. – to cause a micro- or nanoscale structure to stick when you don’t want it to. So, for instance, if you push a cantilever down until it touches a base surface, it may stick when you remove the force you used to push it down.

Some companies actually use this as a way of holding down the cantilever, but in general, the issue comes when trying to release it. Assuming you’re not intentionally using stiction as your hold-down mechanism, DelfMEMS says that the traditional approach to avoiding stiction issues when opening the contact is to rely on mechanical force sufficient to overcome the stiction. And this mechanical force is typically provided by using a really stiff beam structure, located relatively far from the contact surface. That way it’s pulling away hard.

The downside of that is that you need a very high voltage – on the order of 50-100 V – to bend the thing when you want to actuate it.

DelfMEMS has a different structure. Viewed from the side, you can think of it like a bridge, except that, instead of being anchored at the end of the beam, there are two pillars placed in from the ends, and the bridge rests on them. This means that the beam can flex both so that the middle bows down, with the ends raising up, and so that the middle bows up, with the ends flexing down. The key is that they put actuating electrodes both in the middle, to pull the middle down and make contact, and under the ends, to pull the ends down, which raises the middle and breaks the contact. In other words, you get electrical help in both directions. And that reduces the voltages needed to less than 20 V.

This appears to be the essence of what they bring to the table, although they talk about other details in a whitepaper on their website. You can find out more about them and their recent funding round in their release.

Leave a Reply

featured blogs
Jun 18, 2021
It's a short week here at Cadence CFD as we celebrate the Juneteenth holiday today. But CFD doesn't take time off as evidenced by the latest round-up of CFD news. There are several really... [[ Click on the title to access the full blog on the Cadence Community sit...
Jun 17, 2021
Learn how cloud-based SoC design and functional verification systems such as ZeBu Cloud accelerate networking SoC readiness across both hardware & software. The post The Quest for the Most Advanced Networking SoC: Achieving Breakthrough Verification Efficiency with Clou...
Jun 17, 2021
In today’s blog episode, we would like to introduce our newest White Paper: “System and Component qualifications of VPX solutions, Create a novel, low-cost, easy to build, high reliability test platform for VPX modules“. Over the past year, Samtec has worked...
Jun 14, 2021
By John Ferguson, Omar ElSewefy, Nermeen Hossam, Basma Serry We're all fascinated by light. Light… The post Shining a light on silicon photonics verification appeared first on Design with Calibre....

featured video

Kyocera Super Resolution Printer with ARC EV Vision IP

Sponsored by Synopsys

See the amazing image processing features that Kyocera’s TASKalfa 3554ci brings to their customers.

Click here for more information about DesignWare ARC EV Processors for Embedded Vision

featured paper

What is a Hall-effect sensor?

Sponsored by Texas Instruments

Are you considering a Hall-effect sensor for your next design? Read this technical article to learn how Hall-effect sensors work to accurately measure position, distance and movement. In this article, you’ll gain insight into Hall-effect sensing theory, topologies, common use cases and the different types of Hall-effect sensors available today: Hall-effect switches, latches and linear sensors.

Click to read more

featured chalk talk

ROHM's KX132-1211 & KX134-1211 Accelerometers

Sponsored by Mouser Electronics and ROHM Semiconductor

Machine health monitoring is a key benefit in the Industry 4.0 revolution. Integrating data from sensors for vibration detection, motion detection, angle measurement and more can give a remarkably accurate picture of machine health, and timely warning of impending failure. In this episode of Chalk Talk, Amelia Dalton chats with Alex Chernyakov of ROHM Semiconductor about the key considerations in machine health monitoring, and how a new line of accelerometers for industrial applications can help.

Click here for more information about Kionix / ROHM Semiconductor KX134 & KX132 Tri-axis Digital Accelerometers