Touch-sensitive concrete was invented by Andre Broekman, a Civil Engineering PhD candidate at the University of Pretoria, and might revolutionize home and business security in South Africa.
Broekman demonstrated the concept in his concrete macro keyboard prototype. The technology essentially uses a touch breakdown sensor to measure changes in the capacitance over a concrete medium.
The technology could be used in home and business security solutions, removing the need for equipment such as electric fencing and alarm systems.
Wynand Steyn, head of the Civil Engineering department at the University of Pretoria, told MyBroadband that it could be adapted to send an alert — to you or your security services — as soon as someone touches your boundary wall.
This could reduce the need for electric fencing, allowing South Africans to protect their properties and businesses with an invisible solution.
He explained that it could be further adapted by dividing the wall into sections, allowing users to pinpoint the location where a potential intruder makes contact.
The technology also has the potential to replace internal alarm systems by implementing it in the flooring of a building.
It could then send an alert when someone walks through different areas of the building.
Broekman explained that the technology could also be used to aid the visually impaired. His prototype keyboard has tactile concrete keys engraved with symbols.
The engraved symbols would give a visually impaired individual a better idea of what button they are pressing.
The concrete keyboard
Broekman’s prototype is programmed to carry out specific macro commands within the Windows operating system.
Dubbed the Raakcrete, the keyboard macros include selecting, cutting, copying and pasting text, opening the task manager, and opening the cryptocurrency exchange Binance.
It also has a button to switch between Linux and Windows modes. The keyboard indicates that it is in Linux mode when the RGB lighting goes green.
The lighting goes blue when the keyboard is in Windows mode.
Each concrete key features a symbol — that Broekman engraved using a computer numeric controlled laser — to indicate what it does.
The surface beneath the keys is a polycarbonate sheet, and Broekman built the other plastic elements using a 3D printer.
When it comes to hardware, the keys sense contact through a capacitive touch sensor that measures changes in capacitance across the concrete medium.
The sensor then relays the information to a Raspberry Pi Pico microcontroller chip programmed with the macro commands.
A small LCD is mounted on the front of the keyboard that displays uptime, which button is pressed, and how many buttons had been pressed during its uptime.
Broekman said he could potentially scale the keyboard down to a third of its current size and that he could improve his design by making the keys thinner.
“If I could re-do it, I would make the buttons a bit thinner to increase the sensitivity,” he said.
He also said that there was a slight input lag with the current version, and thinner keys could help to improve the responsiveness of each touch.
His inspiration for the prototype came to him while working on his PhD thesis when he thought of a solution to automate certain aspects of his work.
Broekman said that the keyboard components were all affordable, and in total, the build cost him R450-R500 and a lot of man-hours.
Images of the concrete keyboard are included below.
Source: https://mybroadband.co.za/news/gadgets/437998-touch-sensitive-concrete-technology-could-revolutionise-security-in-south-africa.html