Force Modulation Research Articles

Low frequency photothermal excitation of AFM microcantilevers

Photothermal excitation at frequencies below the mechanical resonance of the atomic force microscopy (AFM) microcantilever can be utilized in force modulation microscopy, fast force displacement curve acquisition, and tip-based mass spectroscopy. To understand the microcantilever bending response in these modes, accurate models of the thermoelastic response of the AFM microcantilever are needed. We study the sub-resonance photothermal vibrational response of coated and uncoated AFM microcantilevers as a function of laser modulation frequency and spot location. The sub-resonance microcantilever response shows distinct thermoelastic regimes. Below the microcantilever's thermal roll-off frequency, the vibration amplitude is mostly constant. Past this frequency, the vibration amplitude decreases with increasing frequency. At modulation frequencies below the thermal roll-off frequency, the most efficient photothermal laser spot to excite harmonic motion is near the free end of both coated and uncoated microcantilevers. For the tested coated microcantilevers, the most efficient photothermal laser location migrates from near the free end of the microcantilever to near the fixed end as modulation frequency increases. For the tested uncoated microcantilever, the most efficient photothermal laser location remains unchanged at the tested frequencies. To predict the bending response of the coated microcantilever, a bilayer bending model is implemented. At low frequencies, this model underpredicts the bending response compared to experiments by up to 90%. This may be due to neglecting microcantilever bending contributed by a through-thickness temperature gradient. Our results illustrate different aspects of the frequency-dependent photothermal laser spot optimization that can guide users to maximizing microcantilever response to a given input power.

Assessment of nanomechanical properties of Candida albicans as an element of the oral mycobiota in healthy subjects – a preliminary study

Abstract In a healthy physiological state, the mucous membrane of the oral cavity creates a suitable environment for the colonization of Candida spp. yeasts. The aim of the study was to analyze the nanomechanical properties of C. albicans cells derived from the oral cavity of healthy people in a biofilm produced in laboratory conditions. Candida spp. were sampled from the oral cavity of healthy individuals. The process of biofilm formation was analyzed using classic microscopic observation enriched with SEM (scanning electron microscope) and the nanomechanical properties of the cells were assessed with the use of the atomic force microscopy technique (AFM). From all isolated strains in the samples collected of the oral cavity healthy people was detected 79% C. albicans. Other isolated species belonged to the group „non-albicans”. The observations of C. albicans carried out in 24-h cultures revealed a tendency of the cells to form a biofilm structure with multilayer cell systems. The diameter of C. albicans cells in this structure was 5.75 µm, and the length of the pseudohyphae was 17.08 µm. The presence of an extracellular substance surrounding the C. albicans cells was detected. The mean value of the adhesion force determined for C. albicans cells was 4.01 nN. Areas with increased hardness (Force Modulation Mode signal; FMM signal) were found mainly in the zones of cells in contact with the glass substrate. The analysis of Candida cells in liquid samples gives satisfactory results, as it prevents unfavorable changes in the cell surface and thus provides more reliable results. The quality of the biofilm is probably related to the nanomechanical properties of C. albicans cells and may consequently contribute to the stability of the biofilm structures and their susceptibility or resistance to antifungal drugs. The presence of Candida spp. especially in companion animals (dogs, cats) poses a risk of their transmission to the human organism. For this reason, it is advisable to undertake additional research to analyze the ability of zoonotic-origin Candida spp. to form biofilms with comparison of the biofilm-formation capacity of species isolated from humans.

A Modular 3-Degrees-of-Freedom Force Sensor for Robot-Assisted Minimally Invasive Surgery Research.

Effective force modulation during tissue manipulation is important for ensuring safe, robot-assisted, minimally invasive surgery (RMIS). Strict requirements for in vivo applications have led to prior sensor designs that trade off ease of manufacture and integration against force measurement accuracy along the tool axis. Due to this trade-off, there are no commercial, off-the-shelf, 3-degrees-of-freedom (3DoF) force sensors for RMIS available to researchers. This makes it challenging to develop new approaches to indirect sensing and haptic feedback for bimanual telesurgical manipulation. We present a modular 3DoF force sensor that integrates easily with an existing RMIS tool. We achieve this by relaxing biocompatibility and sterilizability requirements and by using commercial load cells and common electromechanical fabrication techniques. The sensor has a range of ±5 N axially and ±3 N laterally with errors of below 0.15 N and maximum errors below 11% of the sensing range in all directions. During telemanipulation, a pair of jaw-mounted sensors achieved average errors below 0.15 N in all directions. It achieved an average grip force error of 0.156 N. The sensor is for bimanual haptic feedback and robotic force control in delicate tissue telemanipulation. As an open-source design, the sensors can be adapted to suit other non-RMIS robotic applications.

Investigation of brain mechanisms underlying upper limb function in bilateral cerebral palsy using EEG

ObjectiveFew studies focus on upper limbs in bilateral cerebral palsy (CP) despite potential bimanual deficits. Electroencephalography (EEG) was utilized to investigate brain mechanisms underlying upper limb tasks in bilateral CP and typical development (TD) and relationships to function. Methods26 (14 CP; 12 TD) completed the Box and Blocks Test and transport task with paper, sponge or mixed blocks, while recording EEG and motion data. ResultsGroup effects for path time, path length and Box and Blocks Test revealed bimanual deficits. Four sensorimotor-related EEG clusters were identified. Group effects were found in premotor and dominant motor clusters with greater beta event-related desynchronization (ERD) in CP. Hand and hand by group effects were found in the dominant motor cluster, showing greater ERD with the more affected hand in CP. Condition effects were prominent in the posterior parietal cluster with higher ERD reflecting greater difficulty in force modulation. ConclusionsHigher brain activation associated with greater bimanual deficits is similar to our lower limb findings but contrasts studies in TD or unilateral CP linking higher ERD to greater proficiency. SignificanceBilateral CP shows overreliance on the dominant hemisphere with the less functional hand and higher brain activity presumably related to excessive intracortical connectivity.

Evaluating the effect of non-invasive force feedback on prosthetic grasp force modulation in participants with and without limb loss.

Grasping an object is one of the most common and complex actions performed by humans. The human brain can adapt and update the grasp dynamics through information received from sensory feedback. Prosthetic hands can assist with the mechanical performance of grasping, however currently commercially available prostheses do not address the disruption of the sensory feedback loop. Providing feedback about a prosthetic hand's grasp force magnitude is a top priority for those with limb loss. This study tested a wearable haptic system, i.e., the Clenching Upper-Limb Force Feedback device (CUFF), which was integrated with a novel robotic hand (The SoftHand Pro). The SoftHand Pro was controlled with myoelectrics of the forearm muscles. Five participants with limb loss and nineteen able-bodied participants completed a constrained grasping task (with and without feedback) which required modulation of the grasp to reach a target force. This task was performed while depriving participants of incidental sensory sources (vision and hearing were significantly limited with glasses and headphones). The data were analyzed with Functional Principal Component Analysis (fPCA). CUFF feedback improved grasp precision for participants with limb loss who typically use body-powered prostheses as well as a sub-set of able-bodied participants. Further testing, that is more functional and allows participants to use all sensory sources, is needed to determine if CUFF feedback can accelerate mastery of myoelectric control or would benefit specific patient sub-groups.

Effect of channel dimensions and Reynolds numbers on the turbulence modulation for particle-laden turbulent channel flows

The addition of particles to turbulent flows changes the underlying mechanism of turbulence and leads to turbulence modulation. The important parameters are particle Stokes number, mass loading, particle Reynolds number, fluid bulk Reynolds number, etc., that act together and affect the fluid phase turbulence intensities. In the present study, simulations are carried out for different system sizes (2δ/dp=54,81, and 117) and fluid bulk Reynolds numbers (Reb = 5600 and 13 750) to quantify the extent of turbulence attenuation. Here, δ is the half-channel width, dp is the particle diameter, and Reb is the fluid Reynolds number based on the fluid bulk velocity and channel width. Our study shows that system size and fluid bulk Reynolds number are the two crucial parameters that affect the particle feedback force and turbulence modulation more significantly than the other. The extent of turbulence attenuation increases with an increase in system size for the same volume fraction while keeping the Reynolds number fixed. However, for the same volume fraction and fixed channel dimension, the extent of attenuation is low at a higher Reynolds number. The streamwise turbulent structures are observed to become lengthier and fewer with an increase in system size for the same volume fraction and fixed bulk Reynolds number. However, the streamwise high-speed streaks are smaller, thinner, and closely spaced for higher Reynolds numbers than the lower ones for the same volume fraction. Particle phase velocity statistics for different cases have also been reported.

Muscle preflex response to perturbations in locomotion: In vitro experiments and simulations with realistic boundary conditions.

Neuromuscular control loops feature substantial communication delays, but mammals run robustly even in the most adverse conditions. In vivo experiments and computer simulation results suggest that muscles' preflex-an immediate mechanical response to a perturbation-could be the critical contributor. Muscle preflexes act within a few milliseconds, an order of magnitude faster than neural reflexes. Their short-lasting action makes mechanical preflexes hard to quantify in vivo. Muscle models, on the other hand, require further improvement of their prediction accuracy during the non-standard conditions of perturbed locomotion. Our study aims to quantify the mechanical work done by muscles during the preflex phase (preflex work) and test their mechanical force modulation. We performed in vitro experiments with biological muscle fibers under physiological boundary conditions, which we determined in computer simulations of perturbed hopping. Our findings show that muscles initially resist impacts with a stereotypical stiffness response-identified as short-range stiffness-regardless of the exact perturbation condition. We then observe a velocity adaptation to the force related to the amount of perturbation similar to a damping response. The main contributor to the preflex work modulation is not the change in force due to a change in fiber stretch velocity (fiber damping characteristics) but the change in magnitude of the stretch due to the leg dynamics in the perturbed conditions. Our results confirm previous findings that muscle stiffness is activity-dependent and show that also damping characteristics are activity-dependent. These results indicate that neural control could tune the preflex properties of muscles in expectation of ground conditions leading to previously inexplicable neuromuscular adaptation speeds.

Smooth pursuit eye movements contribute to anticipatory force control during mechanical stopping of moving objects.

When stopping a closing door or catching an object, humans process the motion of inertial objects and apply reactive limb force over short period to interact with them. One way in which the visual system processes motion is through extraretinal signals associated with smooth pursuit eye movements (SPEMs). We conducted three experiments to investigate how SPEMs contribute to anticipatory and reactive hand force modulation when interacting with a virtual object moving in the horizontal plane. We hypothesized that SPEM signals are critical for timing motor responses, anticipatory control of hand force, and task performance. Participants held a robotic manipulandum and attempted to stop an approaching simulated object by applying a force impulse (area under force-time curve) that matched the object's virtual momentum upon contact. We manipulated the object's momentum by varying either its virtual mass or its speed under free gaze or constrained gaze conditions. We examined gaze variables, the timing of hand motor responses, anticipatory force control, and overall task performance. Our results show that when participants were fixated at a designated location instead of following objects with SPEM, anticipatory modulation of hand force before contact decreased. However, constraining gaze by asking participants to fixate did not seem to affect the timing of the motor response or the task performance. Together, these results suggest that SPEMs may be important for anticipatory control of hand force before contact and may also play a critical role in anticipatory stabilization of limb posture when humans interact with moving objects.NEW & NOTEWORTHY We show for the first time that smooth pursuit eye movements (SPEMs) play a role in the modulation of anticipatory control of hand force to stabilize posture against contact forces. SPEMs are critical for tracking moving objects, facilitate processing motion of moving objects, and are impacted during aging and in many neurological disorders, such as Alzheimer's disease and multiple sclerosis. These results provide a novel basis to probe how changes in SPEMs could contribute to deficient limb motor control in older adults and patients with neurological disorders.

Design and optimization of a decoupled serial constant force microgripper for force sensitive objects manipulation

AbstractTo address coupling motion issues and realize large constant force range of microgrippers, we present a serial two-degree-of-freedom compliant constant force microgripper (CCFMG) in this paper. To realize a large output displacement in a compact structure, Scott–Russell displacement amplification mechanisms, bridge-type displacement amplification mechanisms, and lever amplification mechanisms are combined to compensate stroke of piezoelectric actuators. In addition, constant force modules are utilized to achieve a constant force output. We investigated CCFMG’s performances by means of pseudo-rigid body models and finite element analysis. Simulation results show that the proposed CCFMG has a stroke of 781.34 ${\unicode[Times]{x03BC}}\mathrm{m}$ in the X-direction and a stroke of 258.05 ${\unicode[Times]{x03BC}}\mathrm{m}$ in the Y-direction, and the decoupling rates in two directions are 1.1% and 0.9%, respectively. The average output constant force of the clamp is 37.49 N. The amplification ratios of the bridge-type amplifier and the Scott–Russell amplifier are 7.02 and 3, respectively. Through finite element analysis-based optimization, the constant force stroke of CCFMG is increased from the initial 1.6 to 3 mm.

Mitotic phosphorylation of Tau/MAPT modulates cell cycle progression in prostate cancer cells

PurposeTau/MAPT (microtubule associated protein tau) protein is actively studied for the pathologic consequences of its aberrant proteostasis in central nervous system leading to neurodegenerative diseases. Besides its ability to generate insoluble toxic oligomers, Tau homeostasis has attracted attention for its involvement in the formation of the mitotic spindle. This evidence, in association with the description of Tau expression in extra-neuronal tissues, and mainly in cancer tissues, constitutes the rationale for a more in-depth investigation of Tau role also in neoplastic diseases.MethodsIn our study, we investigated the expression of phosphorylated Tau in prostate cancer cell lines with particular focus on the residue Thr231 present in microtubule binding domain.ResultsThe analysis of prostate cancer cells synchronized with nocodazole demonstrated that the expression of Tau protein phosphorylated at residue Thr231 is restricted to G2/M cell cycle phase. The phosphorylated form was unable to bind tubulin and it does not localize on mitotic spindle. As demonstrated by the use of specific inhibitors, the phosphorylation status of Tau is under the direct control of cdk5 and PP2A, while cdk1 activation was able to exert an indirect control. These mechanisms were also active in cells treated with docetaxel, where counteracting the expression of the dephosphorylated form, by kinase inhibition or protein silencing, determined resistance to drug toxicity.ConclusionsWe hypothesize that phosphorylation status of Tau is a key marker for G2/M phase in prostate cancer cells and that the forced modulation of Tau phosphorylation can interfere with the capacity of cell to efficiently progress through G2/M phase.

Nanotransfer-on-Things: From Rigid to Stretchable Nanophotonic Devices

The growing demand for nanophotonic devices has driven the advancement of nanotransfer printing (nTP) technology. Currently, the scope of nTP is limited to certain materials and substrates owing to the temperature, pressure, and chemical bonding requirements. In this study, we developed a universal nTP technique utilizing covalent bonding-based adhesives to improve the adhesion between the target material and substrate. Additionally, the technique employed plasma-based selective etching to weaken the adhesion between the mold and target material, thereby enabling the reliable modulation of the relative adhesion forces, regardless of the material or substrate. The technique was evaluated by printing four optical materials on nine substrates, including rigid, flexible, and stretchable substrates. Finally, its applicability was demonstrated by fabricating a ring hologram, a flexible plasmonic color filter, and extraordinary optical transmission-based strain sensors. The high accuracy and reliability of the proposed nTP method were verified by the performance of nanophotonic devices that closely matched numerical simulation results.

Early motor skill acquisition in healthy older adults: brain correlates of the learning process.

Motor skill learning is a crucial process at all ages. However, healthy aging is often accompanied by a reduction in motor learning capabilities. This study characterized the brain dynamics of healthy older adults during motor skill acquisition and identified brain regions associated with changes in different components of performance. Forty-three subjects participated in a functional magnetic resonance imaging study during which they learned a sequential grip force modulation task. We evaluated the continuous changes in brain activation during practice as well as the continuous performance-related changes in brain activation. Practice of the motor skill was accompanied by increased activation in secondary motor and associative areas. In contrast, visual and frontal areas were less recruited as task execution progressed. Subjects showed significant improvements on the motor skill. While faster execution relied on parietal areas and was inversely associated with frontal activation, accuracy was related to activation in primary and secondary motor areas. Better performance was achieved by the contribution of parietal regions responsible for efficient visuomotor processing and cortical motor regions involved in the correct action selection. The results add to the understanding of online motor learning in healthy older adults, showing complementary roles of specific networks for implementing changes in precision and speed.

Effects of stochastic forces on the nonlinear behaviour of a silicon nitride membrane nanoelectromechanical resonator

In this work, we present the effects of stochastic force generated by white noise on the nonlinear dynamics of a circular silicon nitride membrane. By tuning the membrane to the Duffing nonlinear region, detected signals switching between low- and high-amplitudes have been observed. They are generated by noise-assisted random jumps between bistable states at room temperature and exhibit high sensitivity to the driving frequency. Through artificially heating different mechanical vibration modes by external input of white noise, the switching rate exhibits exponential dependence on the effective temperature and follows with Kramer‘s law. Furthermore, both the measured switching rate and activation energy exhibit sensitivity to the width of the hysteresis window in nonlinear response and the driving force, which is in qualitative agreement with the theoretical descriptions. Besides, white noise-induced hysteresis window squeezing and bifurcation point shifting have also been observed, which are attributed to the stochastic force modulation of the spring constant of the membrane. These studies are carried out in an all-electric operating scheme at room temperature, paving the way for the exploration of probability distribution-based functional elements that can be massively integrated on-chip.

Vibration Suppression Technology of Integrated NC Machining of Lightweight Monolithic Panel

The new generation spacecraft module is formed by spinning as a whole, and then the whole module is processed by integrated numerical control. Due to the characteristics of the large diameter and thin wall of the module, it is easy to produce vibration in the processing. In this paper, aiming at the vibration problem of integrated CNC machining cabin body, a method of using reconfigurable fixture internal support to suppress the vibration of weak rigid cabin body overall processing is proposed, and the ANSYS finite element analysis software is used to simulate and analyze the internal support force. The results show that the thickness uniformity of the bottom skin is similar, the dimensional accuracy is higher, and the effect of suppressing cutting chatter is obvious. This paper also improves the design of the milling tool with an unequal helix angle, adds DLC tool coating, and increases the tool rake angle. The simulation results of cutting force based on the FORCE module show that the cutting force is reduced by 31% and chatter in machining is suppressed compared with that before the tool is improved. Through the cycloid milling strategy, the wrap angle between the tool and the workpiece is reduced. It reduces the cutting force, reduces the cutting heat, and ensures the consistency of the product wall thickness and the roughness requirements. The experimental results show that these methods can effectively suppress the vibration in the processing and control the thickness of the integrated numerical control processing panel between 1.47-1.77 mm.

Design to Reduce Modulated Vibration in Fractional-Slot Concentrated-Windings PM Machines Considering Slot–Pole Combination

The superior torque performance and unsatisfactory vibration are the inherent contradiction issue in fractional-slot concentrated-windings (FSCW) permanent magnet (PM) machines. This article aims to reduce the modulated vibration in FSCW PM machines while preserving their great torque performance. First, the contradictory relationship between the torque performance and the vibration of FSCW PM machines is revealed from the perspective of the slot–pole combination. Then, the radial force modulation of the FSCW PM machine is investigated from the aspects of spatial order and magnitude modulation. Subsequently, a new vibration reduction design methodology is presented, which combines the optimal slot opening coefficient and modified slot–pole combination. Finally, the prototype of a 12-slot/14-pole FSCW PM machine is manufactured, and several simulated and experimental verifications are carried out to validate the theoretical analysis.

Quantitative Analysis of Electromagnetic Forces by Decoupling Air-Gap Field Modulation and Force Modulation in Rotor-Permanent-Magnet Machines

This article proposes a quantitative analysis model for the electromagnetic forces in rotor-permanent-magnet (rotor-PM) machines, decoupling the air-gap field modulation and the force modulation. First, a unified analytical model of the equivalent concentrated forces (ECFs) is deduced based on the air-gap flux density (AFD) harmonics. Second, the air-gap field modulation and the force modulation are decoupled by the ECF coefficient. Then, to determine the contributions of the modulated AFD harmonics, a quantitative analytical method is proposed. On this basis, the vibration performance of a 12-slot/10-pole (12s/10p) interior PM machine is investigated considering the modulation effect. The results reveal that the influences of rotation speed, PM-excited field, and armature field on the vibration can be clearly represented by the proposed method. Finally, the modal test and the acceleration measurement are conducted to validate the analysis.

Statistical study on the derailment factor considering the weak correlation of lateral-vertical wheel-rail forces of a vehicle-bridge system

This paper proposes a stochastic method to solve the weak correlation of lateral-vertical forces when the train crosses a bridge. This method treats the Kalker creep equation with Taylor series and uses the moment statistical method to approximate the numerical characteristics of the nonlinear terms of the equation. The variance recursive method, mean recursive method, and lateral linear creep force modulation function are proposed. Based on these methods, the approximate numerical solutions for the standard deviation of the lateral linear creep force and the correlation coefficient of the lateral-vertical forces are obtained and verified by Monte Carlo method (MCM). Under certain preconditions, the derailment factor considering the correlation of the wheel-rail forces obeys the Approximate Cauchy Distribution, which is verified by the Kolmogorov–Smirnov test. The correctness of the proposed method is validated comparing the similarity of the derailment factor extreme value cumulative distribution function curve obtained by MCM. The case of a 6-car Pioneer EMU running through a 3-span 32 m simply-supported bridge is concerned by the proposed method and it is found that there is a significant difference with different traffic intense of the railway.

On the Annual and Semi-Annual Components of Variations in Extent of Arctic and Antarctic Sea-Ice

In this paper, the 1978–2022 series of northern (NHSI) and southern (SHSI) hemisphere sea ice extent are submitted to singular spectral analysis (SSA). The trends are quasi-linear, decreasing for NHSI (by 58,300 km2/yr) and increasing for SHSI (by 15,400 km2/yr). The amplitude of annual variation in the Antarctic is double that in the Arctic. The semi-annual components are in quadrature. The first three oscillatory components of both NHSI and SHSI, at 1, 1/2, and 1/3 yr, account for more than 95% of the signal variance. The trends are respectively 21 (Antarctic) and 4 times (Arctic) less than the amplitudes of the annual components. We next analyze variations in pole position (PM for polar motion, coordinates m1, m2) and length of day (lod). Whereas the SSA of the lod is dominated by the same first three components as sea ice, the SSA of the PM contains only the 1-yr forced annual oscillation and the Chandler 1.2-yr component. The 1-yr component of NHSI is in phase with that of the lod and in phase opposition with m1, while the reverse holds for the 1-yr component of SHSI. The semi-annual component appears in the lod and not in m1. The annual and semi-annual components of NHSI and SHSI are much larger than the trends, leading us to hypothesize that a geophysical or astronomical forcing might be preferable to the generally accepted forcing factors. The lack of modulation of the largest (SHSI) forced component does suggest an alternate mechanism. In Laplace’s theory of gravitation, the torques exerted by the Moon, Sun, and planets play the leading role as the source of forcing (modulation), leading to changes in the inclination of the Earth’s rotation axis and transferring stresses to the Earth’s envelopes. Laplace assumes that all masses on and in the Earth are set in motion by astronomical forces; more than variations in eccentricity, it is variations in the inclination of the rotation axis that lead to the large annual components of melting and re-freezing of sea-ice.

Immersive security personnel training module for active shooter events

There is a need to prepare for emergencies such as active shooter events. Emergency response training drills and exercises are necessary to train for such events as we are unable to predict when emergencies do occur. There has been progress in understanding human behavior, unpredictability, human motion synthesis, crowd dynamics, and their relationships with active shooter events, but challenges remain. This paper presents an immersive security personnel training module for active shooter events in an indoor building. We have created an experimental platform for conducting active shooter drills for training that gives a fully immersive feel of the situation and allow one to perform virtual evacuation drills. The security personnel training module also incorporates four sub-modules namely 1) Situational assessment module, 2) Individual officer intervention module, 3) Team Response Module, and 4) Rescue Task Force module. We have developed an immersive virtual reality training module for active shooter events using an Oculus for course of action, visualization, and situational awareness for active shooter events as shown in Fig.1. The immersive security personnel training module aims to get information about the emergency situation inside the building. The dispatched officer will verify the active shooter situation in the building. The security personnel should find a safe zone in the building and secure the people in that area. The security personnel should also find the number and location of persons in possible jeopardy. Upon completion of the initial assessment, the first security personnel shall advise communications and request resources as deemed necessary. This will allow determining whether to take immediate action alone or with another officer or wait until additional resources are available. After successfully gathering the information, the personnel needs to update the info to their officer through a communication device.

Immersive security personnel training module for active shooter events

There is a need to prepare for emergencies such as active shooter events. Emergency response training drills and exercises are necessary to train for such events as we are unable to predict when emergencies do occur. There has been progress in understanding human behavior, unpredictability, human motion synthesis, crowd dynamics, and their relationships with active shooter events, but challenges remain. This paper presents an immersive security personnel training module for active shooter events in an indoor building. We have created an experimental platform for conducting active shooter drills for training that gives a fully immersive feel of the situation and allow one to perform virtual evacuation drills. The security personnel training module also incorporates four sub-modules namely 1) Situational assessment module, 2) Individual officer intervention module, 3) Team Response Module, and 4) Rescue Task Force module. We have developed an immersive virtual reality training module for active shooter events using an Oculus for course of action, visualization, and situational awareness for active shooter events as shown in Fig.1. The immersive security personnel training module aims to get information about the emergency situation inside the building. The dispatched officer will verify the active shooter situation in the building. The security personnel should find a safe zone in the building and secure the people in that area. The security personnel should also find the number and location of persons in possible jeopardy. Upon completion of the initial assessment, the first security personnel shall advise communications and request resources as deemed necessary. This will allow determining whether to take immediate action alone or with another officer or wait until additional resources are available. After successfully gathering the information, the personnel needs to update the info to their officer through a communication device.