From "touch" to "sensing": the revolutionary application of piezoelectric testing technology in the biological industry

Bailibo Testing will discuss with you the revolutionary application of piezoelectric testing technology in the biological industry. In the wave of cross-integration of modern biomedicine and engineering technology, sensors, as the key "window" for obtaining biological signals, are undergoing profound changes. Piezoelectric testing technology, as a detection method that can realize the mutual conversion of mechanical energy and electrical energy, is setting off a revolution in the fields of biological detection, clinical diagnosis and implantable medical equipment due to its unique advantages such as high sensitivity, no need for labels, and instant response.

1. Label-free detection and point-of-care diagnosis

Traditional biological detection often requires complex fluorescent labeling of samples, which is not only time-consuming but may also interfere with the natural activity of biomolecules. Piezoelectric sensors, specifically quartz crystal microbalances (QCM), break this limitation. Its working principle is similar to an extremely precise "nanoscale": when the substance to be measured (such as a virus, a specific protein or a DNA fragment) binds to the recognition molecule on the sensor surface, small changes in mass will cause changes in the oscillation frequency of the quartz crystal.

In the field of point-of-care testing (POCT), this feature shows great potential. Combining deep learning technology, researchers have developed a portable piezoelectric film microbalance platform that uses smartphones to collect acoustic signals for analysis. Experiments show that this platform can achieve extremely high classification accuracy and provide a low-cost, high-efficiency solution for accurate screening of infectious diseases in resource-poor areas. From cancer biomarkers to specific pathogens, piezoelectric sensors are becoming powerful tools for point-of-care diagnostics due to their label-free nature.

2. Tactile feedback and tissue elastography

In minimally invasive surgery, the lack of the surgeon's "feel" is a long-standing pain point. Traditional medical devices cannot sense the hardness of tissue and can easily cause unnecessary damage. The emergence of piezoelectric tactile sensors has equipped medical robots with sensitive "fingertips".

Researchers have designed a miniature piezoelectric tactile sensor, which is only 2.0 mm in size and can be installed on a medical endoscope. By exploiting the differential response of components of varying stiffness to contact forces, the sensor is able to accurately measure the elastic modulus of biological tissue. This means that when removing tumors, doctors can use the signals fed back by the sensors to distinguish between hardened cancerous tissue and healthy soft tissue, thereby accurately locating blood vessels and improving the quality of surgery. This technology extends the doctor's touch to the microscopic level, realizing "what you see is what you feel."

3. Intelligent surgical tools and low-damage implantation

In brain-computer interfaces and ultra-minimally invasive surgeries, how to avoid damage to biological tissues while accurately puncturing is a recognized technical problem. The piezoelectric effect plays the role of "killing two birds with one stone" here.

A university research team has developed an integrated piezoelectric module that combines high-frequency vibration-assisted puncture and real-time force sensing into one. Utilizing the inverse effect of the piezoelectric material, the probe generates high-frequency micro-vibrations, which can smoothly penetrate the biofilm like "a hot knife cutting butter" and reduce the puncture resistance by about 33%. At the same time, the positive effect is used to monitor the penetration force in real time, with an accuracy error of less than 1%. This technology not only reduces brain tissue damage when implanting brain-computer interface electrodes, but also provides a new paradigm for precision operations such as single-cell puncture.

4. Towards flexible wearable and implantable devices

With the advancement of materials science, piezoelectric materials are bidding farewell to their past “hard and brittle” image. A new organic piezoelectric film developed by a university team is as soft as human skin and even the aorta. This material can not only convert tiny deformations of heartbeat and pulse into electrical signals, but also has good biocompatibility, heralding the arrival of the next generation of implantable self-powered sensors.

At the same time, electronic skin made of flexible piezoelectric materials such as polyvinylidene fluoride can not only be attached to the wrist to monitor pulse waves, but can even be attached to the throat to assist deaf and mute people to speak by identifying vocal cord vibrations. Since piezoelectric materials can also collect the mechanical energy of human body movement, future pacemakers may no longer need batteries and can operate solely on heartbeat drive.