Technology Overview
Baran’s EVERSWITCH touch metal technology is based on stand-alone piezoelectric modules that can be arranged in a myriad of configurations from individual switches to multi-function switch arrays and keypads.   The technology uses the piezoelectric effect (the property exhibited by certain crystals that generate voltage when subjected to pressure) to create switches and keypads that are completely sealed, impervious to the environment, operate from -40 to +125ºC (at 100% RH), and contain no moving parts to fail or deteriorate over time.

With no moving parts, EVERSWITCH products can last indefinitely even in the most extreme operating conditions.  Switch failure due to motion, friction, dirt, moisture, vandalism or ice is eliminated; our switches frequently outlast the equipment they are installed in.  Our piezoelectric switch mimics a standard dry contact mechanical switch and requires no current to operate and works on either AC or DC.

The basis for Baran’s patented EVERSWITCH technology is the VPM (Versatile Piezo Module).   (See Figure 1 below)  The VPM is press-fit into its housing, so that when pressed, the piezoelectric ceramic material produces a corresponding change in voltage, which passes through a conductive connecting material to a MOSFET circuit board.  Our press-fit VPM module eliminates the need for a solder connection to the delicate piezo ceramic material and creates a uniform 125msec minimum switch closure.  This is a significant improvement over all other piezo switches which are typically rated at 20msec minimum, making them prone to false activations, and causing de-bounce issues.


The switch activation area, which is typically 1mm thick, (see Figure 2 below) actually flexes 1-2 microns with each pressing.   This is completely imperceptible to an operator and is so minimal that there is zero wear and tear on the switch structure itself.


This same technology is applied to keypads utilizing one-piece milled housings for ultimate durability.  The switch signals go to microcontrollers that contain any needed application software, as well as any interface protocols, eliminating the need for ASIC’s and their associated cost and complications.  LED, VFD, LCD, TFT or other display technologies can be easily integrated, as well as proximity, RFID, biometric, or other customer-specific electronics.   Keypad outputs can be simply matrixed, or supplied in any of the more common communication protocols.  Housing options range from anodized Aluminum, Stainless Steel, polycarbonate and other plastics.

Electrical Specifications:

Voltage Handling: Up to 24 Volts, AC or DC
Current Capacity: 0.2 Amps (up to 10A optional)
Contact actuation pulse duration: 125 – 300 mSec (typical)
Contact actuation force: 3- 5 Newtons
Output: Matrix, RS-232, 485, PS2 and USB
Operational temp range: -40ºC to +125ºC (at 100% RH)
Cycles: 50 Million
“On” resistance: < 10 ohms
“Off” resistance: > 5 ohms

Benefits of EVERSWITCH Piezoelectric Technology:  
•    Extremely rugged – tested and proven for 50,000,000 cycles
•    All circuitry is completely potted and sealed.
•    Needs no input power source and usable in either AC or DC circuits
•    EVERSWITCH neither produces ESD, EMI, RFI, nor is susceptible to it.
•    Meets or exceeds IP-69K ratings – impervious to rain, sleet, ice (submersible)
•    Will pass CE, CSA, UL, FM, ATEX Class 1, Div.1, VDE, ETL, FAA testing
•    Provides a 125 mSec pulse for effective communications with PLC’s, PIC’s, etc.
•    Factory certified to ISO 9001:2000.  Meets or exceeds MIL-Std 810C and MIL-Std 202E
•    Text and graphics are hard-coat permanently anodized – stainless steel is laser-etched
•    Tamper and vandal-proof – ideal for industrial, high traffic, heavy use, or public applications.
•    Momentary, toggle (On/Off), and continuous – also available, slide, timer and field programmable functions
•    Usable with gloved, wet, or dry hands or any tool.
•    Readily customized in small production runs
•    Excellent value for challenging environments