Self-Healing Robots and Military Equipment, Sci-Fi or Reality? How TVS Power Diodes Are Helping Design the Future of Military Tech


Robots for different military platforms are soon becoming the norm, but not everyone is convinced. One of the factors preventing their full acceptance is whether they can perform independently and not become an additional burden. Besides, in the heat of a mission, when something breaks, none of the options are appealing. Personnel could stop to repair it or destroy it, if slowing down is out of the question and it is imperative that enemy forces do not get hold of it. They could also abandon it covertly in hopes of recovering it later, or in the hopes that friendly forces find it.

In light of these problems, the concept of self-healing technology is quite appealing. Research into this phenomenon brings us closer to Sci-Fi movie scenes where a wounded robot grows a limb back, or a gaping hole fills up to make the affected part as good as new.

Just the way a physical defect can stop normal operation, an electrical defect in the form of energetic power surges can interrupt operations and destroy connected components in the process. MDE Semiconductor, Inc. offers a range of power TVS diodes (voltage clamps) to prevent such outages in complex and sensitive electronics found in military systems.

Even though it is still early days according to scientists working on various military self-healing projects, the achievements so far are promising for applications such as soldier clothing, personal protective equipment, robotic parts, prosthetic limbs, advanced data storage equipment, and power generating electronics. Let’s explore further and discover how much closer science fiction is to becoming reality.


What Are Self-Healing Materials?

The search for self-healing materials was fueled by the significant cost of repairing damages. Protective measures (for example, coatings and more durable materials) are a step in the right direction. Yet when these measures encounter faults beyond their capabilities, the issue remains.

Inspired by nature, researchers thought self-healing as a potential solution to disrupt the cycle of damage and repair or replacement with the added advantage of not needing manual intervention.

Broadly speaking, self-healing processes can be classified into extrinsic or intrinsic. As their names imply, extrinsic methods rely on an outside stimulus, such as an additive to facilitate the process. Intrinsic methods take advantage of the behavior of the molecules in the material’s structure and their affinity to bond together. To qualify as self-healing, materials would need to detect damage and initiate the repair process all on their own.

Military vehicles, ships, and aircraft stand a better chance of yielding better returns over their lifetimes if they can repair themselves. Revolutionary self-healing materials will be characterized by sensing capabilities which in turn need to be supported by electronic systems. MDE Semiconductor, Inc. are experts in electronic circuit protection with a range of power TVS diodes that prevent power anomalies from interfering with reliability and high-performance.


Types of Self-Healing Materials

Researchers have attempted to incorporate self-healing abilities into numerous materials including metals, ceramics, cement, and polymers. For their similarities to organic polymers that heal themselves, investigations with synthetic polymers have endured as the most popular. The healing ability of a polymer depends on the repeating units of its molecular structure and its capacity to reorganize and bond.

Scientists are also pushing the boundaries to include biological components in their polymeric structures to create hybrids between synthetic and organic materials. Success will require that any unique combination of materials be fit for purpose. Likewise, MDE Semiconductor, Inc. understands that in designing unique circuits, some customization may be required for our power TVS diodes to match a given application. We provide custom assemblies built to customer-specific designs ensuring maximum protection performance.


Self-healing for Military Applications, Some Achievements

When it comes to constructing parts for military use, any proposed materials will have a lot of hurdles to jump including passing compliance tests. This conundrum among countless others is what research organizations are working to solve. Notable accomplishments for military applications that have been publicized include the following:

Promising Wearable Tech

Work done by a research team in Pennsylvania State University towards wearable self-healing materials involved boron nitride nanosheets integrated onto a plastic polymer base layer to produce a stronger material.

The mechanism is as follows, the boron nitride nanosheets would link together once in close proximity and use the electrostatic attraction between the hydrogen bonding groups on their surfaces to trigger the action. The researchers demonstrated successful bonding even after cutting the material up to 10 times.

Another key focus the team is working to improve is that the self-healing material should keep its other characteristics after damage and subsequent repair. The research leader stated, “We envision that if the material is somehow damaged, then the material can repair its mechanical properties and also other functionality.”

Self-healing in the Jaws of a Squid

Collaboration between Scientists at Penn State University, Max Planck Institute for Intelligent Systems in Germany, and the Army Research Office led to the announcement of self-healing potential found in squids. A tough protein allows the squid teeth, the circular appendages used to grab prey to repair itself when damaged.

The researchers, wanting to avoid petroleum-based polymers found this material held a lot of promise. As a result, they devised a method to produce squid ink at scale using bacterial hosts. Their work is an example of creating hybrids between organic and synthetic materials. The researchers designed high-strength polymers based on this natural protein and combinations of other materials, thereby building a library of compounds that could prove useful in military applications in future.

Although still in the research and development phase, one such end product exhibits properties similar to Velcro. The bonds holding the proteins together easily pull apart and can also stitch back together quickly using heat to speed up a 24-hour long process to one that takes mere seconds [1].

Also, once broken down into a powder form, it’s possible to convert back to the original state for a truly biodegradable, biosynthetic self-healing material.

A Floodgate of Possibilities with 3D Printing

Researchers from Texas A&M University and the US Army Combat Capabilities Development Command Army Research Laboratory collaborated to create a self-healing material that was 3D printable and recyclable. One of the scientists commented “Their other desirable characteristics, like 3D printability and the ability to self-heal within seconds, make them suited for not just more realistic prosthetics and soft robotics, but also ideal for broad military applications such as agile platforms for air vehicles and futuristic self-healing aircraft wings.”

Finding the right balance between flexibility and strength consumed early development efforts. Too soft polymers are insufficient for the structural applications required in military platforms. The scientists chemically added polymer chains with two types of cross-linking molecules into a selected parent polymer to increase the stiffness of the resulting product. The self-healing property was due to the reversible chemical bonding in the cross-linking molecules. And beneficial for 3D printing was the similar temperatures at which the crosslinking dissociates for a wide range of stiffness levels.


The Role of Sensors and Artificial Intelligence for Self-Healing

Today’s equipment has built-in diagnostics that help characterize the overall system health and operating performance. Internal components mutually sense the others’ performance based on their dependencies.

Self-healing requires a coordinated effort between sensors to detect damage and actuators that localize the affected region and facilitate the controlled self-healing process. Artificial intelligence and machine learning increase the sensitivity of a system to changes using insights derived from processing terabytes of data exchanged between components. Autonomy is possible when the robot or equipment “knows” it has been damaged and takes the next steps based on the embedded programming.


Power TVS Diodes Facilitate Self-Sufficiency and Reliability by Diverting Transient Overvoltages

Self-sufficiency increases when machines do not need physical input from a human for their operation. This would enable their remote and long-term application wherever possible. These devices rely on efficient sensing, data processing, communications and network connectivity, and, therefore, powerful electronics. With these numerous requirements come complex circuitry in which a power irregularity in one part can propagate and cause damage to connected systems.

Transient Voltage Suppressor diodes (TVS diodes) are circuit protection devices placed strategically to ensure predictable performance by clamping voltage spikes and promoting controlled electric flow. MDE Semiconductor, Inc. manufactures power TVS diodes that are designed to protect sensitive equipment.

Our MAX-20KA Power TVS Diodes Series has surge capabilities up to 20KA (at 8 x 20μsec waveform), and offers excellent clamping capability and fast response times – less than 1.0 μs. These bidirectional TVS diodes cover stand-off voltages from 16 V to 136 V, and are beneficial for high-current applications. Our suite of products is designed to meet the highest standards of protection against voltage surges and electrostatic discharges. We offer technical support and design assistance for any challenge in your unique application.


Omobolanle Bello-Ochende, PhD is a contributing writer for MDE Semiconductor, Inc. in our technological news division.  Omobolanle is based in Cape Town with a PhD in Chemical Engineering.  Bola says, “I tend to lose precious hours finding out how everyday things work, because fundamentals are important! And when I’m not discovering new technologies, you’ll find me unwinding with English period dramas on BBC.”