editor's blog
Subscribe Now

A Diving Board, Water Drop, and Flashlight

Two gentlemen at the Institut d’Electronique, de Microélectronique et de Nanotechnologie (IEMN) at the University of Lille in France, have demonstrating an interesting proof of concept of a new mechanical switching mechanism that relies on the interplay between mechanical and capillary forces as well as how “wet” a drop can get.

The concept is based upon the fact that the wetting properties of a droplet – that is, how easily it spreads out on a surface – can be changed capacitively. Placing a drop on a thin insulator with a semiconductor region below it, and touching the drop above with a conductor, makes the droplet part of a capacitor. The droplet becomes one plate, the semiconductor – p-type in their experiment – is the other plate. Modulating the voltage to which the p-region is biased changes the wetting properties of the droplet, making it sink down or rise up as the bias is modulated. This is “electrowetting.”

Now, by shining plain-old white light on the semiconductor – nothing fancy, no “lasers” – you further modulate the charge in the semiconductor, further affecting the wetting. Presumably this only works with a transparent insulating layer. This is referred to as “photoelectrowetting.” Gesundheit.

Here’s how you make a switch, then. You take a MEMS cantilever and place the droplet right under the tip (or close enough to have some leverage). The cantilever is a spring and wants to stay straight. But once in contact with the droplet, the capillary force makes it “stick” to the surface of the drop. So when the droplet rises or falls, then the cantilever rises and falls with it – as long as the restoring spring force doesn’t overcome the capillary force and break the connection.

Putting it all together, the idea is that, in principle, given this setup, you should be able to use the cantilever as a relay (some portion of it being able to contact another conductor), using white light to activate the switch. The good news is that, because the switching mechanism is capacitive, it makes an extremely low-power switching mechanism (as they point out, it’s like the gate of an MOS transistor, qualitatively).

You can find their complete paper here.

Leave a Reply

featured blogs
Apr 11, 2021
https://youtu.be/D29rGqkkf80 Made in "Hawaii" (camera Ziyue Zhang) Monday: Dynamic Duo 2: The Sequel Tuesday: Gall's Law and Big Ball of Mud Wednesday: Benedict Evans on Tech in 2021... [[ Click on the title to access the full blog on the Cadence Community sit...
Apr 8, 2021
We all know the widespread havoc that Covid-19 wreaked in 2020. While the electronics industry in general, and connectors in particular, took an initial hit, the industry rebounded in the second half of 2020 and is rolling into 2021. Travel came to an almost stand-still in 20...
Apr 7, 2021
We explore how EDA tools enable hyper-convergent IC designs, supporting the PPA and yield targets required by advanced 3DICs and SoCs used in AI and HPC. The post Why Hyper-Convergent Chip Designs Call for a New Approach to Circuit Simulation appeared first on From Silicon T...
Apr 5, 2021
Back in November 2019, just a few short months before we all began an enforced… The post Collaboration and innovation thrive on diversity appeared first on Design with Calibre....

featured video

Meeting Cloud Data Bandwidth Requirements with HPC IP

Sponsored by Synopsys

As people continue to work remotely, demands on cloud data centers have never been higher. Chip designers for high-performance computing (HPC) SoCs are looking to new and innovative IP to meet their bandwidth, capacity, and security needs.

Click here for more information

featured paper

Understanding Functional Safety FIT Base Failure Rate Estimates per IEC 62380 and SN 29500

Sponsored by Texas Instruments

Functional safety standards such as IEC 61508 and ISO 26262 require semiconductor device manufacturers to address both systematic and random hardware failures. Base failure rates (BFR) quantify the intrinsic reliability of the semiconductor component while operating under normal environmental conditions. Download our white paper which focuses on two widely accepted techniques to estimate the BFR for semiconductor components; estimates per IEC Technical Report 62380 and SN 29500 respectively.

Click here to download the whitepaper

Featured Chalk Talk

Keeping Your Linux Device Secure

Sponsored by Siemens Digital Industries Software

Embedded security is an ongoing process, not a one-time effort. Even after your design is shipped, security vulnerabilities are certain to be discovered - even in things like the operating system. In this episode of Chalk Talk, Amelia Dalton chats with Kathy Tufto from Mentor - a Siemens business, about how to make a plan to keep your Linux-based embedded design secure, and how to respond quickly when new vulnerabilities are discovered.

More information about Mentor Embedded Linux®